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Rao S, Sharan K, Chandraguthi SG, Dsouza RN, David LR, Ravichandran S, Mustapha MT, Shettigar D, Uzun B, Kadavigere R, Sukumar S, Ozsahin DU. Advanced Computational Methods for Radiation Dose Optimization in CT. Diagnostics (Basel) 2024; 14:921. [PMID: 38732335 PMCID: PMC11083136 DOI: 10.3390/diagnostics14090921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 04/18/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
BACKGROUND In planning radiotherapy treatments, computed tomography (CT) has become a crucial tool. CT scans involve exposure to ionizing radiation, which can increase the risk of cancer and other adverse health effects in patients. Ionizing radiation doses for medical exposure must be kept "As Low As Reasonably Achievable". Very few articles on guidelines for radiotherapy-computed tomography scans are available. This paper reviews the current literature on radiation dose optimization based on the effective dose and diagnostic reference level (DRL) for head, neck, and pelvic CT procedures used in radiation therapy planning. This paper explores the strategies used to optimize radiation doses, and high-quality images for diagnosis and treatment planning. METHODS A cross-sectional study was conducted on 300 patients with head, neck, and pelvic region cancer in our institution. The DRL, effective dose, volumetric CT dose index (CTDIvol), and dose-length product (DLP) for the present and optimized protocol were calculated. DRLs were proposed for the DLP using the 75th percentile of the distribution. The DLP is a measure of the radiation dose received by a patient during a CT scan and is calculated by multiplying the CT dose index (CTDI) by the scan length. To calculate a DRL from a DLP, a large dataset of DLP values obtained from a specific imaging procedure must be collected and can be used to determine the median or 75th-percentile DLP value for each imaging procedure. RESULTS Significant variations were found in the DLP, CTDIvol, and effective dose when we compared both the standard protocol and the optimized protocol. Also, the optimized protocol was compared with other diagnostic and radiotherapy CT scan studies conducted by other centers. As a result, we found that our institution's DRL was significantly low. The optimized dose protocol showed a reduction in the CTDIvol (70% and 63%), DLP (60% and 61%), and effective dose (67% and 62%) for both head, neck, and pelvic scans. CONCLUSIONS Optimized protocol DRLs were proposed for comparison purposes.
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Affiliation(s)
- Shreekripa Rao
- Department of Radiotherapy and Oncology, Manipal College of Health Professions, Manipal 576104, India (R.N.D.)
| | - Krishna Sharan
- Department of Radiotherapy and Oncology, Kasturba Medical College and Hospital, Manipal 576104, India; (K.S.); (S.G.C.)
| | | | - Rechal Nisha Dsouza
- Department of Radiotherapy and Oncology, Manipal College of Health Professions, Manipal 576104, India (R.N.D.)
| | - Leena R. David
- Department of Medical Imaging Technology, Manipal College of Health Professions, Manipal 576104, India; (L.R.D.); (S.R.); (D.S.)
- Department of Medical Diagnostic Imaging, College of Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Sneha Ravichandran
- Department of Medical Imaging Technology, Manipal College of Health Professions, Manipal 576104, India; (L.R.D.); (S.R.); (D.S.)
| | - Mubarak Taiwo Mustapha
- Operational Research Centre in Healthcare, Near East University, TRNC Mersin 10, Nicosia 99138, Turkey; (M.T.M.); (B.U.)
- Department of Biomedical Engineering, Near East University, TRNC Mersin 10, Nicosia 99138, Turkey
| | - Dilip Shettigar
- Department of Medical Imaging Technology, Manipal College of Health Professions, Manipal 576104, India; (L.R.D.); (S.R.); (D.S.)
| | - Berna Uzun
- Operational Research Centre in Healthcare, Near East University, TRNC Mersin 10, Nicosia 99138, Turkey; (M.T.M.); (B.U.)
- Department of Mathematics, Near East University, TRNC Mersin 10, Nicosia 99138, Turkey
| | - Rajagopal Kadavigere
- Department of Radiodiagnosis and Imaging, Kasturba Medical College and Hospital, Manipal 576104, India;
| | - Suresh Sukumar
- Department of Medical Imaging Technology, Manipal College of Health Professions, Manipal 576104, India; (L.R.D.); (S.R.); (D.S.)
| | - Dilber Uzun Ozsahin
- Department of Medical Diagnostic Imaging, College of Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates
- Operational Research Centre in Healthcare, Near East University, TRNC Mersin 10, Nicosia 99138, Turkey; (M.T.M.); (B.U.)
- Research Institute for Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates
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Oki T, Nagatani Y, Ishida S, Hashimoto M, Oshio Y, Hanaoka J, Uemura R, Watanabe Y. Right main pulmonary artery distensibility on dynamic ventilation CT and its association with respiratory function. Eur Radiol Exp 2024; 8:50. [PMID: 38570418 PMCID: PMC10991550 DOI: 10.1186/s41747-024-00441-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 01/22/2024] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND Heartbeat-based cross-sectional area (CSA) changes in the right main pulmonary artery (MPA), which reflects its distensibility associated with pulmonary hypertension, can be measured using dynamic ventilation computed tomography (DVCT) in patients with and without chronic obstructive pulmonary disease (COPD) during respiratory dynamics. We investigated the relationship between MPA distensibility (MPAD) and respiratory function and how heartbeat-based CSA is related to spirometry, mean lung density (MLD), and patient characteristics. METHODS We retrospectively analyzed DVCT performed preoperatively in 37 patients (20 female and 17 males) with lung cancer aged 70.6 ± 7.9 years (mean ± standard deviation), 18 with COPD and 19 without. MPA-CSA was separated into respiratory and heartbeat waves by discrete Fourier transformation. For the cardiac pulse-derived waves, CSA change (CSAC) and CSA change ratio (CSACR) were calculated separately during inhalation and exhalation. Spearman rank correlation was computed. RESULT In the group without COPD as well as all cases, CSACR exhalation was inversely correlated with percent residual lung volume (%RV) and RV/total lung capacity (r = -0.68, p = 0.003 and r = -0.58, p = 0.014). In contrast, in the group with COPD, CSAC inhalation was correlated with MLDmax and MLD change rate (MLDmax/MLDmin) (r = 0.54, p = 0.020 and r = 0.64, p = 0.004) as well as CSAC exhalation and CSACR exhalation. CONCLUSION In patients with insufficient exhalation, right MPAD during exhalation was decreased. Also, in COPD patients with insufficient exhalation, right MPAD was reduced during inhalation as well as exhalation, which implied that exhalation impairment is a contributing factor to pulmonary hypertension complicated with COPD. RELEVANCE STATEMENT Assessment of MPAD in different respiratory phases on DVCT has the potential to be utilized as a non-invasive assessment for pulmonary hypertension due to lung disease and/or hypoxia and elucidation of its pathogenesis. KEY POINTS • There are no previous studies analyzing all respiratory phases of right main pulmonary artery distensibility (MPAD). • Patients with exhalation impairment decreased their right MPAD. • Analysis of MPAD on dynamic ventilation computed tomography contributes to understanding the pathogenesis of pulmonary hypertension due to lung disease and/or hypoxia in patients with expiratory impairment.
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Affiliation(s)
- Tatsuya Oki
- Department of Radiology, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
| | - Yukihiro Nagatani
- Department of Radiology, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan.
| | - Shota Ishida
- Department of Radiological Technology, Kyoto College of Medical Science, 1-3 Sonobecho Oyamahigashimachi Imakita, Nantan, Kyoto, 622-0041, Japan
| | - Masayuki Hashimoto
- Department of Thoracic Surgery, Takeda General Hospital, 28-1 Ishida Moriminamicho, Fushimi-Ku, Kyoto, 601-1434, Japan
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
| | - Yasuhiko Oshio
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
| | - Jun Hanaoka
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
| | - Ryo Uemura
- Department of Radiology, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
| | - Yoshiyuki Watanabe
- Department of Radiology, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
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Frenzel M, Ucar FA, Brockmann C, Altmann S, Abello MAM, Uphaus T, Ringel F, Korczynski O, Mukhopadhyay A, Sanner AP, Schmidtmann I, Brockmann MA, Othman AE. Comparison of Ultra-High-Resolution and Normal-Resolution CT-Angiography for Intracranial Aneurysm Detection in Patients with Subarachnoid Hemorrhage. Acad Radiol 2024; 31:1594-1604. [PMID: 37821348 DOI: 10.1016/j.acra.2023.08.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 08/23/2023] [Accepted: 08/25/2023] [Indexed: 10/13/2023]
Abstract
RATIONALE AND OBJECTIVES Ruptured intracranial aneurysms (IAs) are the leading cause for atraumatic subarachnoid hemorrhage. In case of aneurysm rupture, patients may face life-threatening complications and require aneurysm occlusion. Detection of the aneurysm in computed tomography (CT) imaging is therefore essential for patient outcome. This study provides an evaluation of the diagnostic accuracy of Ultra-High-Resolution Computed Tomography Angiography (UHR-CTA) and Normal-Resolution Computed Tomography Angiography (NR-CTA) concerning IA detection and characterization. MATERIALS AND METHODS Consecutive patients with atraumatic subarachnoid hemorrhage who received Digital Subtraction Angiography (DSA) and either UHR-CTA or NR-CTA were retrospectively included. Three readers evaluated CT-Angiography regarding image quality, diagnostic confidence and presence of IAs. Sensitivity and specificity were calculated on patient-level and segment-level with reference standard DSA-imaging. CTA patient radiation exposure (effective dose) was compared. RESULTS One hundred and eight patients were identified (mean age = 57.8 ± 14.1 years, 65 women). UHR-CTA revealed significantly higher image quality and diagnostic confidence (P < 0.001) for all readers and significantly lower effective dose (P < 0.001). Readers correctly classified ≥55/56 patients on UHR-CTA and ≥44/52 patients on NR-CTA. We noted significantly higher patient-level sensitivity for UHR-CTA compared to NR-CTA for all three readers (reader 1: 41/41 [100%] vs. 28/34 [82%], reader 2: 41/41 [100%] vs. 30/34 [88%], reader 3: 41/41 [100%] vs. 30/34 [88%], P ≤ 0.04). Segment-level analysis also revealed significantly higher sensitivity for UHR-CTA compared to NR-CTA for all three readers (reader 1: 47/49 [96%] vs. 34/45 [76%], reader 2: 47/49 [96%] vs. 37/45 [82%], reader 3: 48/49 [98%] vs. 37/45 [82%], P ≤ 0.04). Specificity was comparable for both techniques. CONCLUSION We found Ultra-High-Resolution CT-Angiography to provide higher sensitivity than Normal-Resolution CT-Angiography for the detection of intracranial aneurysms in patients with aneurysmal subarachnoid hemorrhage while improving image quality and reducing patient radiation exposure.
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Affiliation(s)
- Marius Frenzel
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (M.F., F.A.U., C.B., S.A., M.A.M., O.K., A.P.S., M.A.B., A.E.O.)
| | - Felix A Ucar
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (M.F., F.A.U., C.B., S.A., M.A.M., O.K., A.P.S., M.A.B., A.E.O.)
| | - Carolin Brockmann
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (M.F., F.A.U., C.B., S.A., M.A.M., O.K., A.P.S., M.A.B., A.E.O.)
| | - Sebastian Altmann
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (M.F., F.A.U., C.B., S.A., M.A.M., O.K., A.P.S., M.A.B., A.E.O.)
| | - Mario A Mercado Abello
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (M.F., F.A.U., C.B., S.A., M.A.M., O.K., A.P.S., M.A.B., A.E.O.)
| | - Timo Uphaus
- Department of Neurology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (T.U.)
| | - Florian Ringel
- Department of Neurosurgery, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (F.R.)
| | - Oliver Korczynski
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (M.F., F.A.U., C.B., S.A., M.A.M., O.K., A.P.S., M.A.B., A.E.O.)
| | | | - Antoine P Sanner
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (M.F., F.A.U., C.B., S.A., M.A.M., O.K., A.P.S., M.A.B., A.E.O.); Technical University, Darmstadt, Germany (A.M., A.P.S.)
| | - Irene Schmidtmann
- Institute for Medical Biostatistics, Epidemiology and Informatics, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (I.S.)
| | - Marc A Brockmann
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (M.F., F.A.U., C.B., S.A., M.A.M., O.K., A.P.S., M.A.B., A.E.O.)
| | - Ahmed E Othman
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany (M.F., F.A.U., C.B., S.A., M.A.M., O.K., A.P.S., M.A.B., A.E.O.).
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Kamdem EF, Fotue AJ, Kouam BBF, Abogo S, Samba ON. Estimation of diagnostic reference levels for pediatric head computed tomography in Yaoundé. RADIATION PROTECTION DOSIMETRY 2024; 200:259-263. [PMID: 38088439 DOI: 10.1093/rpd/ncad298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 11/02/2023] [Accepted: 11/15/2023] [Indexed: 03/05/2024]
Abstract
The diagnostic reference levels (DRLs) are determined from dosimetry studies to compare and manage patient doses in medical imaging procedures. The aim of this work was to establish the first DRLs for pediatric patients during the most common computed tomography (CT) procedures in Yaoundé, Cameroon during routine head CT examinations to know how to improve our clinical practice tomorrow. The sample was classified per age group: ≤ 1-, 1-5-, 5-10- and 10-15-y-old. The retrospective study was used. The proposed DRLs were defined as 75th percentile of the median values of the distributions. In terms of Volume CT Dose Index (CTDIvol) and dose length product (DLP), the DRLs obtained for the ages groups were: 28.6 mGy and 545.8 mGy.cm, 32.6 mGy and 735 mGy.cm, 37.1 mGy and 761.6 mGy.cm and 44.2 mGy and 1081.2 mGy.cm, respectively. DRLs in Yaoundé for DLP were higher than those of comparison literatures. The Yaoundé CTDIvol was higher than the comparison literatures except for the IAEA (2015) values for the three older age groups. The DRLs reported in Yaoundé were compared to Morocco 2020, Switzerland 2018, IAEA 2015 and Iran 2020 values. The estimation of this first DRL for pediatric head CT scan in Yaoundé must be a starting point to spread this investigation towards other examinations and imaging modalities across the country. Therefore, optimization of the CT scan procedures and orderly updates of local DRLs are necessary to improve radioprotection.
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Affiliation(s)
- Eddy F Kamdem
- Condensed Matter, Electronics and Signal Processing Research Unit, Department of Physics, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Alain J Fotue
- Condensed Matter, Electronics and Signal Processing Research Unit, Department of Physics, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Brice B F Kouam
- Department of Radiology, Yaoundé General Hospital, Yaoundé, Cameroon
| | - Serge Abogo
- Department of Radiology, Bafoussam Regional Hospital, Bafoussam, Cameroon
| | - Odette N Samba
- Department of Radiography, National Social Insurance Fund Hospital, Yaoundé, Cameroon
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Melzig C, Hartmann S, Steuwe A, Egger J, Do TD, Geisbüsch P, Kauczor HU, Rengier F, Fink MA. BMI-Adapted Double Low-Dose Dual-Source Aortic CT for Endoleak Detection after Endovascular Repair: A Prospective Intra-Individual Diagnostic Accuracy Study. Diagnostics (Basel) 2024; 14:280. [PMID: 38337796 PMCID: PMC10855180 DOI: 10.3390/diagnostics14030280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/19/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
PURPOSE To assess the diagnostic accuracy of BMI-adapted, low-radiation and low-iodine dose, dual-source aortic CT for endoleak detection in non-obese and obese patients following endovascular aortic repair. METHODS In this prospective single-center study, patients referred for follow-up CT after endovascular repair with a history of at least one standard triphasic (native, arterial and delayed phase) routine CT protocol were enrolled. Patients were divided into two groups and allocated to a BMI-adapted (group A, BMI < 30 kg/m2; group B, BMI ≥ 30 kg/m2) double low-dose CT (DLCT) protocol comprising single-energy arterial and dual-energy delayed phase series with virtual non-contrast (VNC) reconstructions. An in-patient comparison of the DLCT and routine CT protocol as reference standard was performed regarding differences in diagnostic accuracy, radiation dose, and image quality. RESULTS Seventy-five patients were included in the study (mean age 73 ± 8 years, 63 (84%) male). Endoleaks were diagnosed in 20 (26.7%) patients, 11 of 53 (20.8%) in group A and 9 of 22 (40.9%) in group B. Two radiologists achieved an overall diagnostic accuracy of 98.7% and 97.3% for endoleak detection, with 100% in group A and 95.5% and 90.9% in group B. All examinations were diagnostic. The DLCT protocol reduced the effective dose from 10.0 ± 3.6 mSv to 6.1 ± 1.5 mSv (p < 0.001) and the total iodine dose from 31.5 g to 14.5 g in group A and to 17.4 g in group B. CONCLUSION Optimized double low-dose dual-source aortic CT with VNC, arterial and delayed phase images demonstrated high diagnostic accuracy for endoleak detection and significant radiation and iodine dose reductions in both obese and non-obese patients compared to the reference standard of triple phase, standard radiation and iodine dose aortic CT.
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Affiliation(s)
- Claudius Melzig
- Clinic for Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Sibylle Hartmann
- Clinic for Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Andrea Steuwe
- Clinic for Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Jan Egger
- Institute for AI in Medicine, University Medicine Essen, 45147 Essen, Germany
| | - Thuy D. Do
- Clinic for Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Philipp Geisbüsch
- Department of Vascular and Endovascular Surgery, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Department of Vascular and Endovascular Surgery, Klinikum Stuttgart, Katharinenhospital, 70199 Stuttgart, Germany
| | - Hans-Ulrich Kauczor
- Clinic for Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Fabian Rengier
- Clinic for Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Matthias A. Fink
- Clinic for Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
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Rawashdeh M, Bani Yaseen AB, McEntee M, England A, Kumar P, Saade C. Diagnostic reference levels in spinal CT: Jordanian assessments and global benchmarks. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2024; 32:725-734. [PMID: 38189739 DOI: 10.3233/xst-230276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
BACKGROUND To reduce radiation dose and subsequent risks, several legislative documents in different countries describe the need for Diagnostic Reference Levels (DRLs). Spinal radiography is a common and high-dose examination. Therefore, the aim of this work was to establish the DRL for Computed Tomography (CT) examinations of the spine in healthcare institutions across Jordan. METHODS Data was retrieved from the picture archiving and communications system (PACS), which included the CT Dose Index (CTDI (vol) ) and Dose Length Product (DLP). The median radiation dose values of the dosimetric indices were calculated for each site. DRL values were defined as the 75th percentile distribution of the median CTDI (vol) and DLP values. RESULTS Data was collected from 659 CT examinations (316 cervical spine and 343 lumbar-sacral spine). Of the participants, 68% were males, and the patients' mean weight was 69.7 kg (minimum = 60; maximum = 80, SD = 8.9). The 75th percentile for the DLP of cervical and LS-spine CT scans in Jordan were 565.2 and 967.7 mGy.cm, respectively. CONCLUSIONS This research demonstrates a wide range of variability in CTDI (vol) and DLP values for spinal CT examinations; these variations were associated with the acquisition protocol and highlight the need to optimize radiation dose in spinal CT examinations.
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Affiliation(s)
- Mohammad Rawashdeh
- Faculty of Health Sciences, Gulf Medical University, Ajman, UAE
- Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan
| | - Abdel-Baset Bani Yaseen
- Faculty of Health, School of Clinical Science, Queensland University of Technology, Queensland, Australia
| | - Mark McEntee
- Discipline of Medical Imaging and Radiation Therapy, Brookfield Health Sciences, University College Cork, Cork, Ireland
| | - Andrew England
- Discipline of Medical Imaging and Radiation Therapy, Brookfield Health Sciences, University College Cork, Cork, Ireland
| | - Praveen Kumar
- Faculty of Health Sciences, Gulf Medical University, Ajman, UAE
| | - Charbel Saade
- Discipline of Medical Imaging and Radiation Therapy, Brookfield Health Sciences, University College Cork, Cork, Ireland
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Funashima K, Abiko S, Sato K. Novel method for calculating the effective dose using size-specific dose estimates conversion factors in abdomen-pelvis computed tomography. Radiol Phys Technol 2023; 16:506-515. [PMID: 37648948 DOI: 10.1007/s12194-023-00738-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 08/18/2023] [Accepted: 08/19/2023] [Indexed: 09/01/2023]
Abstract
We propose a novel method for calculating the effective dose that closely reflects the individual attenuation, utilizing two conversion coefficients. A total of 180 adult patients who underwent abdomen-pelvis computed tomography were categorized into six groups based on sex and body type. The effective dose was calculated by multiplying the dose-length product with the effective dose conversion coefficient and the size-specific dose estimate conversion factor. The effective dose calculated using a simulation-based dose calculator (WAZA-ARI) was employed as the reference value. The following values, obtained through both methods, were compared within each category: distribution of the effective dose, median effective dose, and relative difference in median effective dose across additional body mass index (BMI) categories. For male patients, no significant disparity was observed in the median effective doses calculated using the two methods. The relative differences in median effective doses across additional BMI categories ranged from - 5 to 6%. Conversely, among female patients, the median effective dose calculated using our method slightly undercut that calculated using WAZA-ARI, with relative differences ranging from - 16 to - 9%. Additionally, relative differences in median effective dose across additional BMI categories ranged from - 18 to - 7%. The median effective dose differed slightly depending on the calculation method because of the different reference phantoms applied in dose calculations. Our proposed method is sensitive to individual size and helps compute a size-specific effective dose.
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Affiliation(s)
- Kentaro Funashima
- Japanese Red Cross Sendai Hospital, 2-43-3, Yagiyamahoncho, Taihaku-ku, Sendai, Miyagi, 982-8501, Japan.
| | - Shigeru Abiko
- Japanese Red Cross Sendai Hospital, 2-43-3, Yagiyamahoncho, Taihaku-ku, Sendai, Miyagi, 982-8501, Japan
| | - Kazuhiro Sato
- Tohoku University Graduate School of Medicine, 2-1 Seiryo-Machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
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Yamamoto Y, Tanabe Y, Kurata A, Yamamoto S, Kido T, Uetani T, Ikeda S, Nakano S, Yamaguchi O, Kido T. Feasibility of four-dimensional similarity filter for radiation dose reduction in dynamic myocardial computed tomography perfusion imaging. FRONTIERS IN RADIOLOGY 2023; 3:1214521. [PMID: 38105799 PMCID: PMC10722229 DOI: 10.3389/fradi.2023.1214521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 11/20/2023] [Indexed: 12/19/2023]
Abstract
Rationale and objectives We aimed to evaluate the impact of four-dimensional noise reduction filtering using a four-dimensional similarity filter (4D-SF) on radiation dose reduction in dynamic myocardial computed tomography perfusion (CTP). Materials and methods Forty-three patients who underwent dynamic myocardial CTP using 320-row computed tomography (CT) were included in the study. The original images were reconstructed using iterative reconstruction (IR). Three different CTP datasets with simulated noise, corresponding to 25%, 50%, and 75% reduction of the original dose (300 mA), were reconstructed using a combination of IR and 4D-SF. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were assessed, and CT-derived myocardial blood flow (CT-MBF) was quantified. The results were compared between the original and simulated images with radiation dose reduction. Results The median SNR (first quartile-third quartile) at the original, 25%-, 50%-, and 75%-dose reduced-simulated images with 4D-SF was 8.3 (6.5-10.2), 16.5 (11.9-21.7), 15.6 (11.0-20.1), and 12.8 (8.8-18.1) and that of CNR was 4.4 (3.2-5.8), 6.7 (4.6-10.3), 6.6 (4.3-10.1), and 5.5 (3.5-9.1), respectively. All the dose-reduced-simulated CTPs with 4D-SF had significantly higher image quality scores in SNR and CNR than the original ones (25%-, 50%-, and 75%-dose reduced vs. original images, p < 0.05, in each). The CT-MBF in 75%-dose reduced-simulated CTP was significantly lower than 25%-, 50%- dose-reduced-simulated, and original CTPs (vs. 75%-dose reduced-simulated images, p < 0.05, in each). Conclusion 4D-SF has the potential to reduce the radiation dose associated with dynamic myocardial CTP imaging by half, without impairing the robustness of MBF quantification.
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Affiliation(s)
- Yuta Yamamoto
- Department of Radiology, Ehime University Graduate School of Medicine, Toon, Japan
| | - Yuki Tanabe
- Department of Radiology, Ehime University Graduate School of Medicine, Toon, Japan
| | - Akira Kurata
- Department of Radiology, Ehime University Graduate School of Medicine, Toon, Japan
- Department of Cardiology, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan
| | - Shuhei Yamamoto
- Department of Radiology, Ehime University Graduate School of Medicine, Toon, Japan
| | - Tomoyuki Kido
- Department of Radiology, Ehime University Graduate School of Medicine, Toon, Japan
| | - Teruyoshi Uetani
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Toon, Japan
| | - Shuntaro Ikeda
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Toon, Japan
| | - Shota Nakano
- Canon Medical Systems Corporation, Otawara, Japan
| | - Osamu Yamaguchi
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Toon, Japan
| | - Teruhito Kido
- Department of Radiology, Ehime University Graduate School of Medicine, Toon, Japan
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Ha NT, Harris M, Bulsara M, Doust J, Kamarova S, McRobbie D, O'Leary P, Parizel PM, Slavotinek J, Wright C, Youens D, Moorin R. Patterns of computed tomography utilisation in injury management: latent classes approach using linked administrative data in Western Australia. Eur J Trauma Emerg Surg 2023; 49:2413-2427. [PMID: 37318517 PMCID: PMC10728237 DOI: 10.1007/s00068-023-02303-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 06/03/2023] [Indexed: 06/16/2023]
Abstract
PURPOSE Whilst computed tomography (CT) imaging has been a vital component of injury management, its increasing use has raised concern regarding ionising radiation exposure. This study aims to identify latent classes (underlying patterns) of CT use over a 3-year period following the incidence of injury and factors predicting the observed patterns. METHOD A retrospective observational cohort study was conducted in 21,544 individuals aged 18 + years presenting to emergency departments (ED) of four tertiary public hospitals with new injury in Western Australia. Mixture modelling approach was used to identify latent classes of CT use over a 3-year period post injury. RESULTS Amongst injured people with at least one CT scan, three latent classes of CT use were identified including a: temporarily high CT use (46.4%); consistently high CT use (2.6%); and low CT use class (51.1%). Being 65 + years or older, having 3 + comorbidities, history with 3 + hospitalisations and history of CT use before injury were associated with consistently high use of CT. Injury to the head, neck, thorax or abdomen, being admitted to hospital after the injury and arriving to ED by ambulance were predictors for the temporarily high use class. Living in areas of higher socio-economic disadvantage was a unique factor associated with the low CT use class. CONCLUSIONS Instead of assuming a single pattern of CT use for all patients with injury, the advanced latent class modelling approach has provided more nuanced understanding of the underlying patterns of CT use that may be useful for developing targeted interventions.
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Affiliation(s)
- Ninh T Ha
- Health Economics and Data Analytics, Curtin School of Population Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.
| | - Mark Harris
- School of Accounting, Economics and Finance, Faculty of Business and Law, Curtin University, Perth, Western Australia, Australia
| | - Max Bulsara
- Institute for Health Research, University of Notre Dame, Fremantle, WA, Australia
- Centre for Health Services Research, School of Population and Global Health, The University of Western Australia, Crawley, Australia
| | - Jenny Doust
- Australian Women and Girls' Health Research Centre, School of Public Health, University of Queensland, Brisbane, Australia
| | - Sviatlana Kamarova
- Health Economics and Data Analytics, Curtin School of Population Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
- School of Health Sciences, University of Sydney, Camperdown, New South Wales, Australia
- Nepean Blue Mountains Local Health District, Kingswood, New South Wales, Australia
| | - Donald McRobbie
- School of Physical Sciences, University of Adelaide, Adelaide, Australia
| | - Peter O'Leary
- Health Economics and Data Analytics, Curtin School of Population Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
- Obstetrics and Gynaecology Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA, Australia
- PathWest Laboratory Medicine, QE2 Medical Centre, Nedlands, WA, Australia
| | - Paul M Parizel
- Medical School, University of Western Australia, Perth, WA, Australia
- Department of Radiology, Royal Perth Hospital, Victoria Square, Perth, WA, 6000, Australia
| | - John Slavotinek
- SA Medical Imaging, SA Health and College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Cameron Wright
- Health Economics and Data Analytics, Curtin School of Population Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
- Fiona Stanley Hospital, 11 Robin Warren Dr, Murdoch, WA, Australia
- Division of Internal Medicine, Medical School, Faculty of Health and Medical Sciences, University of Western, Perth, Australia
- School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - David Youens
- Health Economics and Data Analytics, Curtin School of Population Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
- Centre for Health Services Research, School of Population and Global Health, The University of Western Australia, Crawley, Australia
| | - Rachael Moorin
- Health Economics and Data Analytics, Curtin School of Population Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
- Centre for Health Services Research, School of Population and Global Health, The University of Western Australia, Crawley, Australia
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Zhou Z, Gao Y, Zhang W, Zhang N, Wang H, Wang R, Gao Z, Huang X, Zhou S, Dai X, Yang G, Zhang H, Nieman K, Xu L. Deep Learning-based Prediction of Percutaneous Recanalization in Chronic Total Occlusion Using Coronary CT Angiography. Radiology 2023; 309:e231149. [PMID: 37962501 DOI: 10.1148/radiol.231149] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Background CT is helpful in guiding the revascularization of chronic total occlusion (CTO), but manual prediction scores of percutaneous coronary intervention (PCI) success have challenges. Deep learning (DL) is expected to predict success of PCI for CTO lesions more efficiently. Purpose To develop a DL model to predict guidewire crossing and PCI outcomes for CTO using coronary CT angiography (CCTA) and evaluate its performance compared with manual prediction scores. MATERIALS AND METHODS Participants with CTO lesions were prospectively identified from one tertiary hospital between January 2018 and December 2021 as the training set to develop the DL prediction model for PCI of CTO, with fivefold cross validation. The algorithm was tested using an external test set prospectively enrolled from three tertiary hospitals between January 2021 and June 2022 with the same eligibility criteria. All participants underwent preprocedural CCTA within 1 month before PCI. The end points were guidewire crossing within 30 minutes and PCI success of CTO. Results A total of 534 participants (mean age, 57.7 years ± 10.8 [SD]; 417 [78.1%] men) with 565 CTO lesions were included. In the external test set (186 participants with 189 CTOs), the DL model saved 85.0% of the reconstruction and analysis time of manual scores (mean, 73.7 seconds vs 418.2-466.9 seconds) and had higher accuracy than manual scores in predicting guidewire crossing within 30 minutes (DL, 91.0%; CT Registry of Chronic Total Occlusion Revascularization, 61.9%; Korean Multicenter CTO CT Registry [KCCT], 68.3%; CCTA-derived Multicenter CTO Registry of Japan (J-CTO), 68.8%; P < .05) and PCI success (DL, 93.7%; KCCT, 74.6%; J-CTO, 75.1%; P < .05). For DL, the area under the receiver operating characteristic curve was 0.97 (95% CI: 0.89, 0.99) for the training test set and 0.96 (95% CI: 0.90, 0.98) for the external test set. Conclusion The DL prediction model accurately predicted the percutaneous recanalization outcomes of CTO lesions and increased the efficiency of noninvasively grading the difficulty of PCI. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Pundziute-do Prado in this issue.
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Affiliation(s)
- Zhen Zhou
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Yifeng Gao
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Weiwei Zhang
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Nan Zhang
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Hui Wang
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Rui Wang
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Zhifan Gao
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Xiaomeng Huang
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Shanshan Zhou
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Xu Dai
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Guang Yang
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Heye Zhang
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Koen Nieman
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
| | - Lei Xu
- From the Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd, Chaoyang District, Beijing 100029, China (Z.Z., Y.G., N.Z., H.W., R.W., L.X.); School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China (W.Z., Z.G., H.Z.); Keya Medical Company, Shenzhen, China (X.H.); Department of Cardiology, Chinese PLA General Hospital, Beijing, China (S.Z.); Department of Radiology, The First Hospital of China Medical University, Shenyang, China (X.D.); Cardiovascular Research Centre, Royal Brompton Hospital, London, UK (G.Y.); National Heart and Lung Institute, Imperial College London, London, UK (G.Y.); and Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif (K.N.)
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Rabinowich A, Shendler G, Ben-Sira L, Shiran SI. Pediatric low-dose head CT: Image quality improvement using iterative model reconstruction. Neuroradiol J 2023; 36:555-562. [PMID: 36897057 PMCID: PMC10569199 DOI: 10.1177/19714009231163559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023] Open
Abstract
PURPOSE To evaluate the differences in pediatric non-contrast low-dose head computed tomography (CT) between filtered-back projection and iterative model reconstruction using objective and subjective image quality evaluation. METHODS A retrospective study evaluated children undergoing low-dose non-contrast head CT. All CT scans were reconstructed using both filtered-back projection and iterative model reconstruction. Objective image quality analysis was performed using contrast and signal-to-noise ratios for the supra- and infratentorial brain regions of identical regions of interest on the two reconstruction methods. Two experienced pediatric neuroradiologists evaluated subjective image quality, visibility of structures, and artifacts. RESULTS We evaluated 233 low-dose brain CT scans of 148 pediatric patients. There was a ∼2-fold improvement in the contrast-to-noise ratio between gray and white matter in the infra- and supratentorial regions (p < 0.001) using iterative model reconstruction compared to filtered-back projection. The white and gray matter signal-to-noise ratio improved more than 2-fold using iterative model reconstruction (p < 0.001). Furthermore, radiologists graded anatomical details, gray-white matter differentiation, beam hardening artifacts, and image quality using iterative model reconstructions as superior to filtered-back projection reconstructions. CONCLUSION Iterative model reconstructions had better contrast-to-noise and signal-to-noise ratios with fewer artifacts in pediatric CT brain scans using low-dose radiation protocols. This image quality improvement was demonstrated in the supra- and infratentorial regions. This method thus comprises an important tool for reducing children's exposure while maintaining diagnostic capability.
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Affiliation(s)
- Aviad Rabinowich
- Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Genady Shendler
- Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Liat Ben-Sira
- Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shelly I Shiran
- Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Suter B, Anthis AHC, Zehnder A, Mergen V, Rosendorf J, Gerken LRH, Schlegel AA, Korcakova E, Liska V, Herrmann IK. Surgical Sealant with Integrated Shape-Morphing Dual Modality Ultrasound and Computed Tomography Sensors for Gastric Leak Detection. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301207. [PMID: 37276437 PMCID: PMC10427398 DOI: 10.1002/advs.202301207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/26/2023] [Indexed: 06/07/2023]
Abstract
Postoperative anastomotic leaks are the most feared complications after gastric surgery. For diagnostics clinicians mostly rely on clinical symptoms such as fever and tachycardia, often developing as a result of an already fully developed, i.e., symptomatic, surgical leak. A gastric fluid responsive, dual modality, electronic-free, leak sensor system integrable into surgical adhesive suture support materials is introduced. Leak sensors contain high atomic number carbonates embedded in a polyacrylamide matrix, that upon exposure to gastric fluid convert into gaseous carbon dioxide (CO2 ). CO2 bubbles remain entrapped in the hydrogel matrix, leading to a distinctly increased echogenic contrast detectable by a low-cost and portable ultrasound transducer, while the dissolution of the carbonate species and the resulting diffusion of the cation produces a markedly reduced contrast in computed tomography imaging. The sensing elements can be patterned into a variety of characteristic shapes and can be combined with nonreactive tantalum oxide reference elements, allowing the design of shape-morphing sensing elements visible to the naked eye as well as artificial intelligence-assisted automated detection. In summary, shape-morphing dual modality sensors for the early and robust detection of postoperative complications at deep tissue sites, opening new routes for postoperative patient surveillance using existing hospital infrastructure is reported.
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Affiliation(s)
- Benjamin Suter
- Nanoparticle Systems Engineering LaboratoryInstitute of Energy and Process Engineering (IEPE)Department of Mechanical and Process Engineering (D‐MAVT)ETH ZurichSonneggstrasse 3Zürich8092Switzerland
- Particles‐Biology InteractionsDepartment of Materials Meet LifeSwiss Federal Laboratories for Materials Science and Technology (Empa)Lerchenfeldstrasse 5St. Gallen9014Switzerland
| | - Alexandre H. C. Anthis
- Nanoparticle Systems Engineering LaboratoryInstitute of Energy and Process Engineering (IEPE)Department of Mechanical and Process Engineering (D‐MAVT)ETH ZurichSonneggstrasse 3Zürich8092Switzerland
- Particles‐Biology InteractionsDepartment of Materials Meet LifeSwiss Federal Laboratories for Materials Science and Technology (Empa)Lerchenfeldstrasse 5St. Gallen9014Switzerland
| | - Anna‐Katharina Zehnder
- Nanoparticle Systems Engineering LaboratoryInstitute of Energy and Process Engineering (IEPE)Department of Mechanical and Process Engineering (D‐MAVT)ETH ZurichSonneggstrasse 3Zürich8092Switzerland
| | - Victor Mergen
- Diagnostic and Interventional RadiologyUniversity Hospital ZurichUniversity of ZurichRämistrasse 100Zürich8091Switzerland
| | - Jachym Rosendorf
- Department of SurgeryFaculty of Medicine in PilsenCharles UniversityAlej Svobody 923/80Pilsen32300Czech Republic
- Biomedical CenterFaculty of Medicine in PilsenCharles UniversityAlej Svobody 1655/76Pilsen32300Czech Republic
| | - Lukas R. H. Gerken
- Nanoparticle Systems Engineering LaboratoryInstitute of Energy and Process Engineering (IEPE)Department of Mechanical and Process Engineering (D‐MAVT)ETH ZurichSonneggstrasse 3Zürich8092Switzerland
- Particles‐Biology InteractionsDepartment of Materials Meet LifeSwiss Federal Laboratories for Materials Science and Technology (Empa)Lerchenfeldstrasse 5St. Gallen9014Switzerland
| | - Andrea A. Schlegel
- Department of Surgery and TransplantationSwiss HPB CentreUniversity Hospital ZurichRämistrasse 100Zurich8091Switzerland
- Fondazione IRCCS Ca' GrandaOspedale Maggiore PoliclinicoCentre of Preclinical ResearchMilan20122Italy
- Transplantation Center, Digestive Disease and Surgery Institute and Department of Immunity and Inflammation, Lerner Research InstituteCleveland Clinic9620 Carnegie AveClevelandOH44106United States
| | - Eva Korcakova
- Biomedical CenterFaculty of Medicine in PilsenCharles UniversityAlej Svobody 1655/76Pilsen32300Czech Republic
- Department of Imaging MethodsFaculty of Medicine in Pilsen, Charles UniversityAlej Svobody 80Pilsen30460Czech Republic
| | - Vaclav Liska
- Department of SurgeryFaculty of Medicine in PilsenCharles UniversityAlej Svobody 923/80Pilsen32300Czech Republic
- Biomedical CenterFaculty of Medicine in PilsenCharles UniversityAlej Svobody 1655/76Pilsen32300Czech Republic
| | - Inge K. Herrmann
- Nanoparticle Systems Engineering LaboratoryInstitute of Energy and Process Engineering (IEPE)Department of Mechanical and Process Engineering (D‐MAVT)ETH ZurichSonneggstrasse 3Zürich8092Switzerland
- Particles‐Biology InteractionsDepartment of Materials Meet LifeSwiss Federal Laboratories for Materials Science and Technology (Empa)Lerchenfeldstrasse 5St. Gallen9014Switzerland
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Tabard-Fougère A, de Bodman C, Dhouib A, Bonnefoy-Mazure A, Armand S, Dayer R. Three-Dimensional Spinal Evaluation Using Rasterstereography in Patients with Adolescent Idiopathic Scoliosis: Is It Closer to Three-Dimensional or Two-Dimensional Radiography? Diagnostics (Basel) 2023; 13:2431. [PMID: 37510176 PMCID: PMC10377872 DOI: 10.3390/diagnostics13142431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
(1) Background: Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional (3D) spine deformity. The Cobb angle, evaluated with 2D radiography, is the gold standard to determine curve severity. The primary aim of this study was to evaluate the 3D spinal evaluation with rasterstereography in patients with AIS. The hypothesis was that rasterstereography reached higher accuracy than the gold standard 2D radiography. The second aim was to compare rasterstereography with 3D radiography. The hypothesis was that the rasterstereographic evaluation of patients with severe major scoliosis curves is closer to 3D radiography compared to the gold standard (2D radiography). (2) Methods: This is a prospective comparative study of a consecutive series of 53 patients, with the scoliosis curve evaluated with two 3D methods and the gold standard (2D radiography). (3) Results: The hypothesis that rasterstereography reached higher accuracy than the gold standard 2D radiography was validated for all curves. Even if all curves were highly correlated, both rasterstereography and 2D radiography scoliosis evaluation were underestimated for moderate/severe curves compared to 3D radiography. (4) Conclusions: The rasterstereographic evaluation of major curve scoliosis is not accurate enough to replace 2D radiography for moderate/severe curves. A longitudinal follow-up should be assessed in future studies to define the sensitivity of the detection of a significant change in the scoliotic mild and moderate curve (<40°).
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Affiliation(s)
- Anne Tabard-Fougère
- Division of Pediatric Orthopaedics, Geneva University Hospitals, University of Geneva, 1205 Geneva, Switzerland
| | - Charlotte de Bodman
- Division of Pediatric Orthopaedics, Geneva University Hospitals, University of Geneva, 1205 Geneva, Switzerland
| | - Amira Dhouib
- Department of Radiology, Reseau Hospitalier Neuchatelois, 2000 Neuchatel, Switzerland
| | - Alice Bonnefoy-Mazure
- Kinesiology Laboratory, Geneva University Hospitals and University of Geneva, 1205 Geneva, Switzerland
| | - Stéphane Armand
- Kinesiology Laboratory, Geneva University Hospitals and University of Geneva, 1205 Geneva, Switzerland
| | - Romain Dayer
- Division of Pediatric Orthopaedics, Geneva University Hospitals, University of Geneva, 1205 Geneva, Switzerland
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Taylor K. CORR Insights®: Is the Lifetime Malignancy Risk in United States Military Personnel Sustaining Combat-related Trauma Increased Because of Radiation Exposure From Diagnostic Imaging? Clin Orthop Relat Res 2023; 481:1047-1048. [PMID: 36716089 PMCID: PMC10097527 DOI: 10.1097/corr.0000000000002533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Accepted: 11/28/2022] [Indexed: 01/31/2023]
Affiliation(s)
- Kenneth Taylor
- Chief of the Division of Hand Surgery, Department of Orthopedics and Rehabilitation, Penn State Milton S. Hershey Medical Center, Hershey, PA, USA
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15
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Suliman II, Khouqeer GA, Ahmed NA, Abuzaid MM, Sulieman A. Low-Dose Chest CT Protocols for Imaging COVID-19 Pneumonia: Technique Parameters and Radiation Dose. Life (Basel) 2023; 13:life13040992. [PMID: 37109522 PMCID: PMC10146316 DOI: 10.3390/life13040992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 03/29/2023] [Accepted: 04/02/2023] [Indexed: 04/29/2023] Open
Abstract
Chest computed tomography (CT) plays a vital role in the early diagnosis, treatment, and follow-up of COVID-19 pneumonia during the pandemic. However, this raises concerns about excessive exposure to ionizing radiation. This study aimed to survey radiation doses in low-dose chest CT (LDCT) and ultra-low-dose chest CT (ULD) protocols used for imaging COVID-19 pneumonia relative to standard CT (STD) protocols so that the best possible practice and dose reduction techniques could be recommended. A total of 564 articles were identified by searching major scientific databases, including ISI Web of Science, Scopus, and PubMed. After evaluating the content and applying the inclusion criteria to technical factors and radiation dose metrics relevant to the LDCT protocols used for imaging COVID-19 patients, data from ten articles were extracted and analyzed. Technique factors that affect the application of LDCT and ULD are discussed, including tube current (mA), peak tube voltage (kVp), pitch factor, and iterative reconstruction (IR) algorithms. The CTDIvol values for the STD, LDCT, and ULD chest CT protocols ranged from 2.79-13.2 mGy, 0.90-4.40 mGy, and 0.20-0.28 mGy, respectively. The effective dose (ED) values for STD, LDCT, and ULD chest CT protocols ranged from 1.66-6.60 mSv, 0.50-0.80 mGy, and 0.39-0.64 mSv, respectively. Compared with the standard (STD), LDCT reduced the dose reduction by a factor of 2-4, whereas ULD reduced the dose reduction by a factor of 8-13. These dose reductions were achieved by applying scan parameters and techniques such as iterative reconstructions, ultra-long pitches, and fast spectral shaping with a tin filter. Using LDCT, the cumulative radiation dose of serial CT examinations during the acute period of COVID-19 may have been inferior or equivalent to that of conventional CT.
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Affiliation(s)
- Ibrahim I Suliman
- Department of Physics, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11642, Saudi Arabia
- Deanship of Scientific Research, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11642, Saudi Arabia
| | - Ghada A Khouqeer
- Department of Physics, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11642, Saudi Arabia
| | - Nada A Ahmed
- Faculty of Science, Taibah University, Al Madinah Al Munawwarah 42353, Saudi Arabia
| | - Mohamed M Abuzaid
- Medical Diagnostic Imaging Department, College of Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Abdelmoneim Sulieman
- Radiology and Medical Imaging Department, College of Applied Medical Sciences, Prince Sattam Bin Abdulaziz University, Alkharj 11942, Saudi Arabia
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16
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Salah H, Rabbaa M, Abuljoud M, Babikir E, Alkhorayef M, Tamam N, Tahir D, Sulieman A, Bradley DA. Paediatric effective radiation doses during brain computed tomography angiography procedure. Appl Radiat Isot 2023; 192:110610. [PMID: 36525913 DOI: 10.1016/j.apradiso.2022.110610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 12/06/2022] [Accepted: 12/06/2022] [Indexed: 12/12/2022]
Abstract
In comparison to adults and paediatric are more sensitive to ionizing radiation exposure. Computed tomography (CT) is now the dominant source of medical radiologic tests for patients, accounting for more than 70% of total doses to the general public. Paediatric CT brain scans (with and without contrast) are routinely performed for a variety of clinical reasons. As a result, this parameter must be calculated in order to determine relative radiation risk. The goal of this study is to assess the radiation risk to children during CT brain diagnostic procedures. Three hundred fifty three child patients' radiation risk doses were assessed over the course of a year. The mean and ranged of the children's radiation doses were 40.6 ± 8.8 (27.8-45.8) CTDIvol (mGy) and 850 ± 230 (568.1-1126.4) DLP (mGy.cm) for the brain with contrast medium. For CT brain without contrast, the patients' doses were 40.9 ± 9.4 (14.27-64.07) CTDIvol (mGy), and 866.1 ± 289.3 (203.6-2484.9) DLP (mGy.cm). The characteristics related to the radiation dose were retrieved from the scan protocol generated by the CT system by the participating physicians after each procedure. Furthermore, optimizing the CT acquisition parameter is critical for increasing the benefit while lowering the procedure's radiogenic risk. The patients' radiation dose is comparable with the most previously published studies and international diagnostic reference levels (DRLs). Radiation dose optimization is recommended due to high sensitivity of the paediatric patients to ionizing radiation.
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Affiliation(s)
- H Salah
- INAYA Medical Collage, Nuclear Medicine Department, Riyadh, Saudi Arabia; College of Medical Radiologic Science, Sudan University of Science and Technology, Khartoum, Sudan.
| | - Mohammad Rabbaa
- Radiology Department, Riyadh Care Hospital, Riyadh, Saudi Arabia
| | | | - E Babikir
- Radiologic Technology Program, College of Health and Sport Sciences, University of Bahrain, Sakhir Campus, Zallaq, P.O. Box 32038, Bahrain
| | - M Alkhorayef
- Department of Radiological Sciences, College of Applied Medical Sciences, King Saud University, P.O Box 10219, Riyadh, 11433, Saudi Arabia
| | - N Tamam
- Department of Physics, College of Sciences, Princess Nourah bint Abdulrahman University, P.O Box 84428, Riyadh, 11671, Saudi Arabia
| | - Dahlang Tahir
- Department of Physics, Hasanuddin University, Makassar, 90245, Indonesia
| | - A Sulieman
- Prince Sattam bin Abdulaziz University, College of Applied Medical Sciences, Radiology and Medical Imaging Department, P.O. Box 422, Alkharj, 11942, Saudi Arabia
| | - D A Bradley
- Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford, United Kingdom; Centre for Applied Physics and Radiation Technologies, School of Engineering and Technology, Sunway University, 47500, Bandar Sunway, Selangor, Malaysia
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17
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Parker LA, Moreno-Garijo A, Chilet-Rosell E, Lorente F, Lumbreras B. Gender Differences in the Impact of Recommendations on Diagnostic Imaging Tests: A Retrospective Study 2007-2021. Life (Basel) 2023; 13:life13020289. [PMID: 36836646 PMCID: PMC9965980 DOI: 10.3390/life13020289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 01/22/2023] Open
Abstract
(1) Background: The frequency of imaging tests grew exponentially in recent years. This increase may differ according to a patient's sex, age, or socioeconomic status. We aim to analyze the impact of the Council Directive 2013/59/Euratom to control exposure to radiation for men and women and explore the impact of patients' age and socioeconomic status; (2) Methods: The retrospective observational study that includes a catchment population of 234,424. We included data of CT, mammography, radiography (conventional radiography and fluoroscopy) and nuclear medicine between 2007-2021. We estimated the associated radiation effective dose per test according using previously published evidence. We calculated a deprivation index according to the postcode of their residence. We divided the study in 2007-2013, 2014-2019 and 2020-2021 (the pandemic period). (3) Results: There was an increase in the number of imaging tests received by men and women after 2013 (p < 0.001), and this increase was higher in women than in men. The frequency of imaging tests decreased during the pandemic period (2020-2021), but the frequency of CT and nuclear medicine tests increased even during these years (p < 0.001) and thus, the overall effective mean dose. Women and men living in the least deprived areas had a higher frequency of imaging test than those living in the most deprived areas. (4) Conclusions: The largest increase in the number of imaging tests is due to CTs, which account for the higher amount of effective dose. The difference in the increase of imaging tests carried out in men and women and according to the socioeconomic status could reflect different management strategies and barriers to access in clinical practice. Given the low impact of the available recommendations on the population exposure to radiation and the performance of high-dose procedures such as CT, deserve special attention when it comes to justification and optimization, especially in women.
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Affiliation(s)
- Lucy A. Parker
- Department of Public Health, University Miguel Hernández de Elche, 03550 Alicante, Spain
- CIBER de Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain
| | - Andrea Moreno-Garijo
- Faculty of Pharmacy, University Miguel Hernández de Elche, 03550 Alicante, Spain
| | - Elisa Chilet-Rosell
- Department of Public Health, University Miguel Hernández de Elche, 03550 Alicante, Spain
- CIBER de Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain
| | - Fermina Lorente
- Radiology Department, University Hospital of San Juan de Alicante, Sant Joan d’Alacant, 03550 Alicante, Spain
| | - Blanca Lumbreras
- Department of Public Health, University Miguel Hernández de Elche, 03550 Alicante, Spain
- CIBER de Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain
- Correspondence: ; Tel.: +34-965-919510
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18
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Uemura R, Nagatani Y, Hashimoto M, Oshio Y, Sonoda A, Otani H, Hanaoka J, Watanabe Y. Association of Respiratory Functional Indices and Smoking with Pleural Movement and Mean Lung Density Assessed Using Four-Dimensional Dynamic-Ventilation Computed Tomography in Smokers and Patients with COPD. Int J Chron Obstruct Pulmon Dis 2023; 18:327-339. [PMID: 36945706 PMCID: PMC10024907 DOI: 10.2147/copd.s389075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 02/02/2023] [Indexed: 03/17/2023] Open
Abstract
Purpose To correlate the ratio of the non-dependent to dependent aspects of the maximal pleural movement vector (MPMVND/D) and gravity-oriented collapse ratio (GCRND/D), and the mean lung field density (MLD) obtained using four-dimensional (4D) dynamic-ventilation computed tomography (DVCT) with airflow limitation parameters and the Brinkman index. Materials and Methods Forty-seven patients, including 22 patients with COPD, 13 non-COPD smokers, and 12 non-smokers, with no/slight pleural adhesion confirmed using a thoracoscope, underwent 4D-DVCT with 16 cm coverage. Coordinates for the lung field center, as well as ventral and dorsal pleural points, set on the central trans-axial levels in the median and para-median sagittal planes at end-inspiration, were automatically measured (13-17 frame images, 0.35 seconds/frame). MPMVND/D and GCRND/D were calculated based on MPMV and GCR values for all the included points and the lung field center. MLD was automatically measured in each of the time frames, and the maximal change ratio of MLD (MLDCR) was calculated. These measured values were compared among COPD patients, non-COPD smokers, and non-smokers, and were correlated with the Brinkman index, FEV1/FVC, FEV1 predicted, RV/TLC, and FEF25-75% using Spearman's rank coefficients. Results MPMVND/D was highest in non-smokers (0.819±0.464), followed by non-COPD smokers (0.405±0.131) and patients with COPD (-0.219±0.900). GCRND/D in non-smokers (1.003±1.384) was higher than that in patients with COPD (-0.164±1.199). MLDCR in non-COPD smokers (0.105±0.028) was higher than that in patients with COPD (0.078±0.027). MPMVND/D showed positive correlations with FEV1 predicted (r=0.397, p=0.006), FEV1/FVC (r=0.501, p<0.001), and FEF25-75% (r=0.368, p=0.012). GCRND/D also demonstrated positive correlations with FEV1 (r=0.397, p=0.006), FEV1/FVC (r=0.445, p=0.002), and FEF25-75% (r=0.371, p=0.011). MPMVND/D showed a negative correlation with the Brinkman index (r=-0.398, p=0.006). Conclusion We demonstrated that reduced MPMVND/D and GCRND/D were associated with respiratory functional indices, in addition to a negative association of MPMVND/D with the Brinkman index, which should be recognized when assessing local pleural adhesion on DVCT, especially for ventral pleural aspects.
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Affiliation(s)
- Ryo Uemura
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
- Correspondence: Ryo Uemura; Yukihiro Nagatani, Department of Radiology, Shiga University of Medical Science, Seta-tsukinowa-cho, Otsu, Shiga, Japan, 520-2192, Tel/Fax +81-77-548-2536, Email ;
| | - Yukihiro Nagatani
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Masayuki Hashimoto
- Department of Thoracic Surgery, Kyoto Medical Center, Kyoto, Kyoto, Japan
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Yasuhiko Oshio
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Akinaga Sonoda
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Hideji Otani
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Jun Hanaoka
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Yoshiyuki Watanabe
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
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19
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Zhou Z, Gao Y, Zhang W, Bo K, Zhang N, Wang H, Wang R, Du Z, Firmin D, Yang G, Zhang H, Xu L. Artificial intelligence-based full aortic CT angiography imaging with ultra-low-dose contrast medium: a preliminary study. Eur Radiol 2023; 33:678-689. [PMID: 35788754 DOI: 10.1007/s00330-022-08975-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 05/16/2022] [Accepted: 06/20/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To further reduce the contrast medium (CM) dose of full aortic CT angiography (ACTA) imaging using the augmented cycle-consistent adversarial framework (Au-CycleGAN) algorithm. METHODS We prospectively enrolled 150 consecutive patients with suspected aortic disease. All received ACTA scans of ultra-low-dose CM (ULDCM) protocol and low-dose CM (LDCM) protocol. These data were randomly assigned to the training datasets (n = 100) and the validation datasets (n = 50). The ULDCM images were reconstructed by the Au-CycleGAN algorithm. Then, the AI-based ULDCM images were compared with LDCM images in terms of image quality and diagnostic accuracy. RESULTS The mean image quality score of each location in the AI-based ULDCM group was higher than that in the ULDCM group but a little lower than that in the LDCM group (all p < 0.05). All AI-based ULDCM images met the diagnostic requirements (score ≥ 3). Except for the image noise, the AI-based ULDCM images had higher attenuation value than the ULDCM and LDCM images as well as higher SNR and CNR in all locations of the aorta analyzed (all p < 0.05). Similar results were also seen in obese patients (BMI > 25, all p < 0.05). Using the findings of LDCM images as the reference, the AI-based ULDCM images showed good diagnostic parameters and no significant differences in any of the analyzed aortic disease diagnoses (all K-values > 0.80, p < 0.05). CONCLUSIONS The required dose of CM for full ACTA imaging can be reduced to one-third of the CM dose of the LDCM protocol while maintaining image quality and diagnostic accuracy using the Au-CycleGAN algorithm. KEY POINTS • The required dose of contrast medium (CM) for full ACTA imaging can be reduced to one-third of the CM dose of the low-dose contrast medium (LDCM) protocol using the Au-CycleGAN algorithm. • Except for the image noise, the AI-based ultra-low-dose contrast medium (ULDCM) images had better quantitative image quality parameters than the ULDCM and LDCM images. • No significant diagnostic differences were noted between the AI-based ULDCM and LDCM images regarding all the analyzed aortic disease diagnoses.
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Affiliation(s)
- Zhen Zhou
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2, Anzhen Road, Chaoyang District, Beijing, 100029, China
| | - Yifeng Gao
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2, Anzhen Road, Chaoyang District, Beijing, 100029, China
| | - Weiwei Zhang
- School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China
| | - Kairui Bo
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2, Anzhen Road, Chaoyang District, Beijing, 100029, China
| | - Nan Zhang
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2, Anzhen Road, Chaoyang District, Beijing, 100029, China
| | - Hui Wang
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2, Anzhen Road, Chaoyang District, Beijing, 100029, China
| | - Rui Wang
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2, Anzhen Road, Chaoyang District, Beijing, 100029, China
| | - Zhiqiang Du
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2, Anzhen Road, Chaoyang District, Beijing, 100029, China
| | - David Firmin
- Cardiovascular Research Centre, Royal Brompton Hospital, London, SW3 6NP, UK.,National Heart and Lung Institute, Imperial College London, London, SW7 2AZ, UK
| | - Guang Yang
- Cardiovascular Research Centre, Royal Brompton Hospital, London, SW3 6NP, UK.,National Heart and Lung Institute, Imperial College London, London, SW7 2AZ, UK
| | - Heye Zhang
- School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China
| | - Lei Xu
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2, Anzhen Road, Chaoyang District, Beijing, 100029, China.
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20
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Kim JH, Jeon UB, Jang JY, Kim TU, Ryu H, Yeom JA, Roh J. Efficacy of single-session 99.5% ethanol sclerotherapy for incidentally found simple renal cysts. Medicine (Baltimore) 2022; 101:e32114. [PMID: 36550842 PMCID: PMC9771283 DOI: 10.1097/md.0000000000032114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Simple renal cysts are the most common masses in the kidney. Most are asymptomatic and are incidentally detected on imaging examinations performed for other reasons. This study aimed to compare the results of 40 and 120 minutes ethanol sclerotherapies that were performed in a single session to treat incidentally found simple renal cysts. We retrospectively reviewed 63 renal cysts in 62 patients treated by single session percutaneous ethanol sclerotherapy. Thirty-one patients with 32 cysts underwent a 40 minutes sclerotherapy (group A), and 31 patients with 31 cysts underwent a 120 minutes retention technique (group B). Under ultrasonographic and fluoroscopic guidance, cystic fluid was completely aspirated, and 50% of the aspirated volume was replaced with 99.5% ethanol (a maximum of 100 mL). Imaging follow-up of the patients was performed 3 months after sclerotherapy. The technical success rates were 100% in both groups. Eighteen patients (29.0%) were symptomatic (flank pain or discomfort). Indications of the other patients were large cysts (>5 cm; 46%) and an increment in the diameter on serial studies (25.4%). A significant difference between the 2 groups in terms of age, cyst diameter, volume of aspirated fluid, volume of injected ethanol, and percentage of reduction in cyst diameter (P > .05) was not found. After treatment, flank pain or discomfort resolved in 17 of 18 (94.4%) symptomatic patients. One patient complained of persistent flank pain; however, no significant abnormality was detected on post-procedural computed tomography images. There were no other complications after therapy in the 2 groups. Single session ethanol sclerotherapy with a 40 minutes retention technique is an effective, safe, and cost-effective method for the treatment of incidentally found simple renal cysts. Although the procedural time was reduced, there was no significant difference in therapeutic efficacy between the 40 and 120 minutes therapies.
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Affiliation(s)
- Jin Hyeok Kim
- Department of Radiology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Ung Bae Jeon
- Department of Radiology, Pusan National University Yangsan Hospital, Yangsan, Korea
- Department of Radiology, School of Medicine, Pusan National University, Yangsan, Korea
- * Correspondence: Ung Bae Jeon, Department of Radiology, Pusan National University Yangsan Hospital, 20 Geumo-ro, Mulgeum-eup, Yangsan, Gyeongnam 50612, Korea (e-mail: )
| | - Joo Yeon Jang
- Department of Radiology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Tae Un Kim
- Department of Radiology, Pusan National University Yangsan Hospital, Yangsan, Korea
- Department of Radiology, School of Medicine, Pusan National University, Yangsan, Korea
| | - Hwaseong Ryu
- Department of Radiology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Jeong A Yeom
- Department of Radiology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Jieun Roh
- Department of Radiology, Pusan National University Yangsan Hospital, Yangsan, Korea
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21
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Al-Sharydah AM, Hegazi TM, Al-Othman AY, Al-Aftan MS, Al-Shehri SS. The Impact of Data Management on the Achievable Dose and Efficiency of Computed Tomography During the COVID-19 Era: A Facility-Based Ambispective Study. J Multidiscip Healthc 2022; 15:2385-2397. [PMID: 36281342 PMCID: PMC9587732 DOI: 10.2147/jmdh.s383957] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/06/2022] [Indexed: 11/11/2022] Open
Abstract
Purpose This study primarily aimed to evaluate the effectiveness of computational data management and analytical software for establishing departmental diagnostic reference levels (DRLs) for computed tomography (CT) scanning in clinical settings, and monitor achievable doses (ADs) for CT imaging, particularly during the coronavirus disease 2019 (COVID-19) era. Secondarily, it aimed to correlate these standards with national and international benchmarks. Patients and Methods This ambidirectional cohort study enrolled 4668 patients (6419 CT-based examinations) who visited King Fahd Hospital of the University from May 25, 2021, to November 4, 2021. Participants' demographic data were acquired from their electronic medical charts, in addition to all corresponding CT-dose determinant parameters. The study was divided into two phases (pre- and post-data management) based on the implementation of digital data management software. Results In both phases of the study, the size-specific dose estimate (SSDE) was the most significant confounder of dose determination compared to the dose-length product (DLP) and computed tomography dose index (CTDI) (P = 0.003). The head was the most frequently imaged body region (pre-implementation, 1051 examinations [35.1%]; post-implementation, 1071 examinations [31.3%]; P = 0.001), followed by the abdominal region (pre-implementation, 616 examinations [20.6%]; post-implementation, 256 examinations [7.48%]; P = 0.001). Based on the SSDE, DLP, and volume CTDI, the average per-section radiation exposure among organ-based scanning type was highest for the lumbar spine during the pre- and post-implementation periods. Conclusion Data management software enabled the establishment of DRLs and reduction of ADs in CT examinations, which consequently improved key performance indicators, despite the ergonomic complexities of COVID-19. Institutions are encouraged to apply DRLs and ADs via automatic systems that monitor patient dose indices to evaluate aggregate results.
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Affiliation(s)
- Abdulaziz Mohammad Al-Sharydah
- Diagnostic and Interventional Radiology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Al-Khobar City, Eastern Province, Saudi Arabia
| | - Tarek Mohammed Hegazi
- Diagnostic and Interventional Radiology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Al-Khobar City, Eastern Province, Saudi Arabia,Correspondence: Tarek Mohammed Hegazi, Diagnostic and Interventional Radiology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Al-Khobar City, Eastern Province, Saudi Arabia, Tel +966138966877 (EXT: 2007), Email
| | - Abdullah Yousef Al-Othman
- Diagnostic and Interventional Radiology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Al-Khobar City, Eastern Province, Saudi Arabia
| | - Mohammad Saad Al-Aftan
- Diagnostic and Interventional Radiology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Al-Khobar City, Eastern Province, Saudi Arabia
| | - Sultan Salman Al-Shehri
- Diagnostic and Interventional Radiology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Al-Khobar City, Eastern Province, Saudi Arabia
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22
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Kamdem EF, Samba ON, Manemo CT, Kouam BBF, Abogo S, Tambe J, Amougou JCM, Guegang E, Zeh OF, Moifo B, Nguemgne C, Nana NFN, Fotue AJ. ESTABLISHMENT OF LOCAL DIAGNOSTIC REFERENCE LEVEL FOR ROUTINE PAEDIATRIC COMPUTED TOMOGRAPHY EXAMINATIONS IN BAFOUSSAM WEST CAMEROON. RADIATION PROTECTION DOSIMETRY 2022; 198:815-820. [PMID: 35718757 DOI: 10.1093/rpd/ncac143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 04/28/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
The main purpose of this study was to determine local diagnostic reference level (LDRL) for routine computed tomography (CT) examination in Bafoussam, western Cameroon. The exposure parameters and dose quantities were collected manually. This retrospective, evaluative and comparative study was conducted to determine LDRLs for routine head CT examination in Bafoussam, to optimize these procedures in the region. The 75th percentile values of the calculated volume CT dose index (CTDIvol) and dose length product (DLP) were proposed as LDRL. The sample was classified in four age groups: < 1, 1-5, 5-10 and 10-15 y. The LDRLs obtained for the four age groups were: 24 mGy and 381.32 mGy.cm, 42.5 mGy and 875.55 mGy.cm, 45.85 mGy and 939.62 mGy.cm, 57.12 mGy and 1222.3 mGy.cm, respectively. The 75th percentile CTDIvol and DLP dose values for this study are higher than international values. We propose a coordinating discussions and collaboration about patient's and specific equipment's change information's, between radiologists, medical imaging technicians and medical physicist, which can reduce absorbed doses and improved medical practice in hospitals.
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Affiliation(s)
- Eddy Fotso Kamdem
- Mesoscopic and Multilayers Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 479, Dschang, Cameroon
| | | | - Cedric Tetchoka Manemo
- Mesoscopic and Multilayers Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 479, Dschang, Cameroon
| | | | - Serge Abogo
- Department of Radiology, National Social Insurance Fund Hospital, Yaoundé, Cameroon
| | - Joshua Tambe
- Department of Radiology, Limbe Regional Hospital, Limbe, Cameroon
| | | | - Emilienne Guegang
- Department of Radiography, Yaoundé General Hospital, Yaoundé, Cameroon
| | - Odile Fernande Zeh
- Department of Radiology, Yaounde Gynaeco-Obstetric and Pediatric Hospital, Yaoundé, Cameroon
| | - Boniface Moifo
- Department of Radiology, Yaounde Gynaeco-Obstetric and Pediatric Hospital, Yaoundé, Cameroon
| | | | | | - Alain Jervé Fotue
- Mesoscopic and Multilayers Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 479, Dschang, Cameroon
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Bouaoun A, Ben Omrane L, Douira Khomssi W. Towards the establishment of national diagnostic reference levels in Tunisia: a multicentre survey in paediatric CT. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2022; 42:031503. [PMID: 35671750 DOI: 10.1088/1361-6498/ac767a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
This work focuses on the determination of the radiation doses for a total sample of 916 children, categorised into four age groups (<1, 1-5, <5-10, <10-15 years) undergoing the most frequent paediatric CT scans performed in different scan facilities in Tunisia in order to establish the national diagnostic reference levels (DRLs). Dose evaluation concerned the dosimetric indicators: volume computed tomography dose index (CTDIvol)and dose-length product (DLP). The different paediatric CT protocols and practices were also evaluated. The results show a large variation in doses between different radiology departments. For head scans, the respective DRLs for children aged <1, 1-5, 5-10 and 10-15 years were 26, 38, 51 and 51 mGy, respectively, for CTDIvoland 384, 664, 873 and 978 mGy cm, respectively, for DLP. For the chest, the equivalent respective DRLs were 8, 10, 12 and 15 mGy for CTDIvoland 118, 330, 442 and 526 mGy cm for DLP. For the abdomen, the respective DRLs were 9, 13, 19 and 18 mGy for CTDIvoland 353, 485, 592 and 1073 mGy cm for DLP. This study shows that the optimisation of paediatric CT procedures should be a priority, especially within regional hospitals. The implementation of corrective actions will take place after the initial DRLs. These actions, including recommendations and guidelines to good practice, should be a joint effort of all stakeholders, including health authorities, the radiation protection regulator, professional societies and universities.
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Affiliation(s)
- Abir Bouaoun
- University of Tunis El Manar, Higher Institute of Medical Technologies of Tunis (ISTMT), LR13ES07 Laboratory of Biophysics and Medical Technologies, Tunis, Tunisia
| | - Latifa Ben Omrane
- University of Tunis El Manar, Higher Institute of Medical Technologies of Tunis (ISTMT), LR13ES07 Laboratory of Biophysics and Medical Technologies, Tunis, Tunisia
- National Centre of Radiation protection (CNRP), Tunis, Tunisia
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Jiang L, Jowkar N, Bhagavatula SK, Levesque VM, Walsh MF, Kapur T, Shyn PB. PET and CT Contributions to Patient Dose and Personnel Exposure from Radiation During PET/CT-Guided Tumor Ablations. J Vasc Interv Radiol 2022; 33:1234-1239. [PMID: 35817359 DOI: 10.1016/j.jvir.2022.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 05/14/2022] [Accepted: 07/03/2022] [Indexed: 11/28/2022] Open
Abstract
This study sought to quantify positron emission tomography (PET) and computed tomography (CT) components of patient dose and personnel radiation exposure during PET/CT-guided tumor ablations, and to assess the utility of a rolling lead shield for operator protection. Two operators performed 21 PET/CT-guided ablations behind a custom 25 mm lead shield with mid-chest to mid-thigh coverage. Mean patient dose per procedure was 3.90 ± 1.13 mSv (11.3%) from PET and 30.51 ± 19.05 mSv (88.7%) from CT. Mean primary and secondary operator exposures outside neck-level thyroid shields were 0.05 mSv and 0.02 mSv per procedure, respectively. Radiation exposure behind the rolling lead shield, inside primary operator's thyroid shield, and on other personnel were below measurable threshold cumulatively over 21 procedures. Mean PET exposure at continuous close proximity to patient was 0.02 mSv per procedure. PET doses to patient and personnel were small; the rolling lead shield provided limited benefit.
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Affiliation(s)
- Liwei Jiang
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115
| | - Nick Jowkar
- Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115
| | - Sharath K Bhagavatula
- Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115
| | - Vincent M Levesque
- Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115
| | - Mark F Walsh
- Department of Health Physics, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115
| | - Tina Kapur
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115
| | - Paul B Shyn
- Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115.
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Erem G, Ameda F, Otike C, Olwit W, Mubuuke AG, Schandorf C, Kisolo A, Kawooya MG. Adult Computed Tomography examinations in Uganda: Towards determining the National Diagnostic Reference Levels. BMC Med Imaging 2022; 22:112. [PMID: 35690743 PMCID: PMC9188687 DOI: 10.1186/s12880-022-00838-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 06/02/2022] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Diagnostic Reference Levels (DRLs), typically set at the 75th percentile of the dose distribution from surveys conducted across a broad user base using a specified dose-measurement protocol, are recommended for radiological examinations. There is a need to develop and implement DRLs as a standardisation and optimisation tool for the radiological protection of patients at Computed Tomography (CT) facilities. METHODS This was a retrospective cross-sectional study conducted in seven (7) different CT scan facilities in which participants were recruited by systematic random sampling. The study variables were dose length product (DLP) and volume-weighted CTDI (CTDIvol) for the radiation doses for head, chest, abdomen and lumbar spine CT examinations. The DRLs for CTDIvol and DLP were obtained by calculating the 3rd quartiles of the radiation doses per study site by anatomical region. The national diagnostic reference levels were determined by computation of DRLs using the 75th centile of the median values. RESULTS A total of 574 patients were examined with an average age of 47.1 years. For CTDIvol estimates; there was a strong positive significant relationship between the CTDIvol and examination mAs (rs = 0.9017, p-value < 0.001), and reference mAs (rs = 0.0.7708, p-value < 0.001). For DLP estimates; there was a moderate positive significant relationships between DLP and total mAs (rs = 0.6812, p-value < 0.001), reference mAs (rs = 0.5493, p-value < 0.001). The DRLs were as follows; for head CT scan - the average median CTDIvol was 56.02 mGy and the DLP was 1260.3 mGy.cm; for Chest CT, the CTDI volume was 7.82 mGy and the DLP was 377.0 mGy.cm; for the abdomen CT, the CTDI volume 12.54 mGy and DLP 1418.3 mGy.cm and for the lumbar spine 19.48 mGy and the DLP was 843 mGy.cm, respectively. CONCLUSION This study confirmed the need to optimize the CT scan parameters in order to lower the national DRLs. This can be achieved by extensive training of all the CT scan radiographers on optimizing the CT scan acquisition parameters. Continuous dose audits are also advised with new equipment or after every three years to ensure that values out of range are either justified or further investigated.
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Affiliation(s)
- Geoffrey Erem
- Department of Radiology, School of Medicine, Makerere University, Kampala, Uganda. .,Clinical Epidemiology Unit, School of Medicine, Makerere University, Kampala, Uganda.
| | - Faith Ameda
- Department of Radiology, School of Medicine, Makerere University, Kampala, Uganda
| | - Caroline Otike
- Clinical Epidemiology Unit, School of Medicine, Makerere University, Kampala, Uganda
| | - William Olwit
- Department of Radiology, School of Medicine, Makerere University, Kampala, Uganda
| | - Aloysius G Mubuuke
- Department of Radiology, School of Medicine, Makerere University, Kampala, Uganda
| | - Cyril Schandorf
- Department of Nuclear Safety and Security, School of Nuclear and Allied Sciences, University of Ghana, Accra, Ghana
| | - Akisophel Kisolo
- Department of Nuclear Physics, Makerere University, Kampala, Uganda
| | - Michael G Kawooya
- Department of Radiology, School of Medicine, Makerere University, Kampala, Uganda.,Department of Radiology, Ernest Cook Ultrasound Research and Education Institute (ECUREI), Kampala, Uganda
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Uushona V, Boadu M, Nyabanda R, Diagne M, Inkoom S, Issahaku S, Hasford F, Haiduwa P, Koteng A, Omondi B, Diop AY, Gilley DB. ESTABLISHMENT OF REGIONAL DIAGNOSTIC REFERENCE LEVELS IN ADULT COMPUTED TOMOGRAPHY FOR FOUR AFRICAN COUNTRIES: A PRELIMINARY SURVEY. RADIATION PROTECTION DOSIMETRY 2022; 198:414-422. [PMID: 35596952 DOI: 10.1093/rpd/ncac074] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 04/09/2022] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
This preliminary study aims towards the establishment of regional diagnostic reference levels (DRLs) for routine adult computed tomography (CT) examinations. The study was performed on 54 CT facilities from four African countries (Ghana, Kenya, Namibia and Senegal) and the results compared with international DRLs. Data were collected from facilities using a structured questionnaire provided by the International Atomic Energy Agency. Dose descriptors (volume computed tomography dose index [CTDIvol] and dose length product [DLP]) evaluations were performed on CT head and body phantoms for head, chest and abdomen CT examination protocols using standard methods. The estimated dose indices were compared with console-displayed dose values. Experienced radiologists accepted the diagnostic image quality of the images as per departmental imaging requirements. Median CTDIvol and DLP data from each facility were compiled to estimate the typical dose in each country. National DRLs were established based on the 75th percentile of median values, whereas the regional DRLs were based on the median of the national DRLs. Comparison of measured CTDIvol with console values of all facilities in all four countries was within 20% as recommended. The established CTDIvol DRLs for head CT, chest CT and abdomen CT were 60.9 mGy, 15.2 mGy and 15.7 mGy, respectively. Similarly, that of DLP, DRLs were 1259 mGy.cm, 544 mGy.cm and 737 mGy.cm, respectively for head CT, chest CT and abdomen CT. The established DRLs from this study were comparable to DRLs from other countries with some variations. This study would serve as baseline for establishment of a more generalized regional adult CT DRLs for Africa.
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Affiliation(s)
- Vera Uushona
- National Radiation Protection Authority of Namibia, Ministry of Health and Social Services, Windhoek, Namibia
| | - Mary Boadu
- Ghana Atomic Energy Commission, Accra, Ghana
| | - Rose Nyabanda
- Department of Radiology, Kenyatta National Hospital, Nairobi Kenya
| | - Magatte Diagne
- University Teaching Hospital-Senegal, Institut Curie, Hôpital Universitaire le Dantec, BP, Dakar, Senegal
| | | | | | | | - Paulus Haiduwa
- Nuclear Medicine Department, Windhoek Central Hospital, Windhoek, Namibia
| | | | - Bob Omondi
- Department of Radiology, Kenyatta National Hospital, Nairobi Kenya
| | - Adji Yaram Diop
- University Teaching Hospital-Senegal, Institut Curie, Hôpital Universitaire le Dantec, BP, Dakar, Senegal
| | - Debbie Bray Gilley
- Radiation Protection of Patients Unit, Radiation Safety and Monitoring Section, Division of Radiation, Transport and Waste Safety, Department of Nuclear Safety and Security, International Atomic Energy Agency (IAEA), Vienna International Centre, Vienna, Austria
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Assessment of diagnostic reference levels awareness and knowledge amongst CT radiographers in Saudi Arabia. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2022. [DOI: 10.1016/j.jrras.2022.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Peters AA, Huber AT, Obmann VC, Heverhagen JT, Christe A, Ebner L. Diagnostic validation of a deep learning nodule detection algorithm in low-dose chest CT: determination of optimized dose thresholds in a virtual screening scenario. Eur Radiol 2022; 32:4324-4332. [PMID: 35059804 DOI: 10.1007/s00330-021-08511-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 12/06/2021] [Accepted: 12/09/2021] [Indexed: 12/17/2022]
Abstract
OBJECTIVES This study was conducted to evaluate the effect of dose reduction on the performance of a deep learning (DL)-based computer-aided diagnosis (CAD) system regarding pulmonary nodule detection in a virtual screening scenario. METHODS Sixty-eight anthropomorphic chest phantoms were equipped with 329 nodules (150 ground glass, 179 solid) with four sizes (5 mm, 8 mm, 10 mm, 12 mm) and scanned with nine tube voltage/current combinations. The examinations were analyzed by a commercially available DL-based CAD system. The results were compared by a comparison of proportions. Logistic regression was performed to evaluate the impact of tube voltage, tube current, nodule size, nodule density, and nodule location. RESULTS The combination with the lowest effective dose (E) and unimpaired detection rate was 80 kV/50 mAs (sensitivity: 97.9%, mean false-positive rate (FPR): 1.9, mean CTDIvol: 1.2 ± 0.4 mGy, mean E: 0.66 mSv). Logistic regression revealed that tube voltage and current had the greatest impact on the detection rate, while nodule size and density had no significant influence. CONCLUSIONS The optimal tube voltage/current combination proposed in this study (80 kV/50 mAs) is comparable to the proposed combinations in similar studies, which mostly dealt with conventional CAD software. Modification of tube voltage and tube current has a significant impact on the performance of DL-based CAD software in pulmonary nodule detection regardless of their size and composition. KEY POINTS • Modification of tube voltage and tube current has a significant impact on the performance of deep learning-based CAD software. • Nodule size and composition have no significant impact on the software's performance. • The optimal tube voltage/current combination for the examined software is 80 kV/50 mAs.
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Affiliation(s)
- Alan A Peters
- Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Bern University Hospital, University of Bern, Inselspital Bern, 3010, Switzerland.
| | - Adrian T Huber
- Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Bern University Hospital, University of Bern, Inselspital Bern, 3010, Switzerland
| | - Verena C Obmann
- Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Bern University Hospital, University of Bern, Inselspital Bern, 3010, Switzerland
| | - Johannes T Heverhagen
- Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Bern University Hospital, University of Bern, Inselspital Bern, 3010, Switzerland.,Department of BioMedical Research, Experimental Radiology, University of Bern, 3008, Bern, Switzerland.,Department of Radiology, The Ohio State University, Columbus, OH, USA
| | - Andreas Christe
- Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Bern University Hospital, University of Bern, Inselspital Bern, 3010, Switzerland
| | - Lukas Ebner
- Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Bern University Hospital, University of Bern, Inselspital Bern, 3010, Switzerland
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Kouchi T, Tanabe Y, Takemoto T, Yoshida K, Yamamoto Y, Miyazaki S, Fukuyama N, Nishiyama H, Inaba S, Kawaguchi N, Kido T, Yamaguchi O, Kido T. A Novel Quantitative Parameter for Static Myocardial Computed Tomography: Myocardial Perfusion Ratio to the Aorta. J Clin Med 2022; 11:jcm11071816. [PMID: 35407424 PMCID: PMC8999663 DOI: 10.3390/jcm11071816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 02/07/2023] Open
Abstract
We evaluated the feasibility of myocardial perfusion ratio to the aorta (MPR) in static computed tomography perfusion (CTP) for detecting myocardial perfusion abnormalities assessed by single-photon emission computed tomography (SPECT). Twenty-five patients with suspected coronary artery disease who underwent dynamic CTP and SPECT were retrospectively evaluated. CTP images scanned at a sub-optimal phase for detecting myocardial perfusion abnormalities were selected from dynamic CTP images and used as static CTP images in the present study. The diagnostic accuracy of MPR derived from static CTP was compared to those of visual assessment and conventional quantitative parameters such as myocardial CT attenuation (HU) and transmural perfusion ratio (TPR). The area under the curve of MPR (0.84; 95% confidence interval [CI], 0.76−0.90) was significantly higher than those of myocardial CT attenuation (0.73; 95% CI, 0.65−0.79) and TPR (0.76; 95% CI, 0.67−0.83) (p < 0.05). Sensitivity and specificity were 67% (95% CI, 54−77%) and 90% (95% CI, 86−92%) for visual assessment, 51% (95% CI, 39−63%) and 86% (95% CI, 82−89%) for myocardial CT attenuation, 63% (95% CI, 51−74%) and 84% (95% CI, 80−88%) for TPR, and 78% (95% CI, 66−86%) and 84% (95% CI, 80−88%) for MPR, respectively. MPR showed higher diagnostic accuracy for detecting myocardial perfusion abnormality compared with myocardial CT attenuation and TPR.
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Affiliation(s)
- Takanori Kouchi
- Department of Radiology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (T.K.); (T.T.); (K.Y.); (Y.Y.); (N.F.); (H.N.); (N.K.); (T.K.); (T.K.)
| | - Yuki Tanabe
- Department of Radiology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (T.K.); (T.T.); (K.Y.); (Y.Y.); (N.F.); (H.N.); (N.K.); (T.K.); (T.K.)
- Correspondence:
| | - Takumasa Takemoto
- Department of Radiology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (T.K.); (T.T.); (K.Y.); (Y.Y.); (N.F.); (H.N.); (N.K.); (T.K.); (T.K.)
| | - Kazuki Yoshida
- Department of Radiology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (T.K.); (T.T.); (K.Y.); (Y.Y.); (N.F.); (H.N.); (N.K.); (T.K.); (T.K.)
| | - Yuta Yamamoto
- Department of Radiology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (T.K.); (T.T.); (K.Y.); (Y.Y.); (N.F.); (H.N.); (N.K.); (T.K.); (T.K.)
| | - Shigehiro Miyazaki
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (S.M.); (S.I.); (O.Y.)
| | - Naoki Fukuyama
- Department of Radiology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (T.K.); (T.T.); (K.Y.); (Y.Y.); (N.F.); (H.N.); (N.K.); (T.K.); (T.K.)
| | - Hikaru Nishiyama
- Department of Radiology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (T.K.); (T.T.); (K.Y.); (Y.Y.); (N.F.); (H.N.); (N.K.); (T.K.); (T.K.)
| | - Shinji Inaba
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (S.M.); (S.I.); (O.Y.)
| | - Naoto Kawaguchi
- Department of Radiology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (T.K.); (T.T.); (K.Y.); (Y.Y.); (N.F.); (H.N.); (N.K.); (T.K.); (T.K.)
| | - Tomoyuki Kido
- Department of Radiology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (T.K.); (T.T.); (K.Y.); (Y.Y.); (N.F.); (H.N.); (N.K.); (T.K.); (T.K.)
| | - Osamu Yamaguchi
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (S.M.); (S.I.); (O.Y.)
| | - Teruhito Kido
- Department of Radiology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Japan; (T.K.); (T.T.); (K.Y.); (Y.Y.); (N.F.); (H.N.); (N.K.); (T.K.); (T.K.)
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Quantifying and Statistically Modeling Residual Pneumoperitoneum after Robotic-Assisted Laparoscopic Prostatectomy: A Prospective, Single-Center, Observational Study. Diagnostics (Basel) 2022; 12:diagnostics12040785. [PMID: 35453833 PMCID: PMC9030483 DOI: 10.3390/diagnostics12040785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 03/15/2022] [Accepted: 03/15/2022] [Indexed: 11/17/2022] Open
Abstract
Background: Laparoscopic surgery (LS) requires CO2 insufflation to establish the operative field. Patients with worsening pain post-operatively often undergo computed tomography (CT). CT is highly sensitive in detecting free air—the hallmark sign of a bowel injury. Yet, the clinical significance of free air is often confounded by residual CO2 and is not usually due to a visceral injury. The aim of this study was to attempt to quantify the residual pneumoperitoneum (RPP) after a robotic-assisted laparoscopic prostatectomy (RALP). Methods: We prospectively enrolled patients who underwent RALP between August 2018 and January 2020. CT scans were performed on postoperative days (POD) 3, 5, and 7. To investigate potential factors influencing the quantity of RPP, correlation plots were made against common variables. Results: In total, 31 patients with a mean age of 66 years (median 67, IQR 62–70.5) and mean BMI 26.59 (median 25.99, IQR: 24.06–29.24) underwent RALP during the study period. All patients had a relatively unremarkable post-operative course (30/31 with Clavien–Dindo class 0; 1/31 with class 2). After 3, 5, and 7 days, 3.2%, 6.4%, and 32.3% were completely without RPP, respectively. The mean RPP at 3 days was 37.6 mL (median 9.58 mL, max 247 mL, IQR 3.92–31.82 mL), whereas the mean RPP at 5 days was 19.85 mL (median 1.36 mL, max 220.77 mL, IQR 0.19–5.61 mL), and 7 days was 10.08 mL (median 0.09 mL, max 112.42 mL, IQR 0–1.5 mL). There was a significant correlation between RPP and obesity (p = 0.04665), in which higher BMIs resulted in lower initial insufflation volumes and lower RPP. Conclusions: This is the first study to systematically assess RPP after a standardized laparoscopic procedure using CT. Larger patients tend to have smaller residuals. Our data may help surgeons interpreting post-operative CTs in similar patient populations.
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Development of an Irish national policy for the management of pregnant or potentially pregnant patients that are referred for a procedure involving the use of ionising radiation. Eur Radiol 2022; 32:5588-5595. [PMID: 35247090 DOI: 10.1007/s00330-022-08612-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 12/17/2021] [Accepted: 01/24/2022] [Indexed: 11/04/2022]
Abstract
OBJECTIVES The management of pregnant or potentially pregnant patients who are referred for medical imaging procedures involving ionising radiation has proven to be a challenge for healthcare providers in Ireland. This has been confirmed by a number of regulatory agencies including the Environmental Protection Agency who have reported poor compliance with legislation, inadequate documentation and sub-optimal patient care. METHODS An expert group was established to examine the issues that were at the root of these problems and produce recommendations for improvement. The issues highlighted by the group included a lack of clarity and consensus around a number of workflow issues such as exam categorisation, criteria to reasonably rule out pregnancy, dealing with paediatric patients and a protocol to allow urgent high fetal dose examinations to proceed when pregnancy cannot be excluded. The absence of a standardised national pregnancy declaration form was also identified as a contributory factor to poor regulatory compliance. RESULTS The group produced a pregnancy policy template that healthcare providers could adopt which clarified the issues that were identified and included a standardised adult and paediatric pregnancy declaration form. The implementation of the policy template was subsequently assessed via a survey of a number of radiology departments and a representative referrer group. CONCLUSIONS The results of these surveys revealed a substantial uptake of the template along with overall satisfaction with the contents. They also demonstrated a reduction in the use of the clinical waiver system which had been highlighted as a cause of sub-optimal patient care. KEY POINTS • The management of pregnant or potentially pregnant patients referred for medical imaging procedures involving ionising radiation is challenging. • A new national pregnancy policy template was developed by an expert group and has been widely adopted by healthcare institutions in Ireland.
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Reference phantom selection in pediatric computed tomography using data from a large, multicenter registry. Pediatr Radiol 2022; 52:445-452. [PMID: 34866159 PMCID: PMC8857172 DOI: 10.1007/s00247-021-05227-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/09/2021] [Accepted: 10/12/2021] [Indexed: 10/25/2022]
Abstract
BACKGROUND Radiation dose metrics vary by the calibration reference phantom used to report doses. By convention, 16-cm diameter cylindrical polymethyl-methacyrlate phantoms are used for head imaging and 32-cm diameter phantoms are used for body imaging in adults. Actual usage patterns in children remain under-documented. OBJECTIVE This study uses the University of California San Francisco International CT Dose Registry to describe phantom selection in children by patient age, body region and scanner manufacturer, and the consequent impact on radiation doses. MATERIALS AND METHODS For 106,837 pediatric computed tomography (CT) exams collected between Jan. 1, 2015, and Nov. 2, 2020, in children up to 17 years of age from 118 hospitals and imaging facilities, we describe reference phantom use patterns by body region, age and manufacturer, and median and 75th-percentile dose-length product (DLP) and volume CT dose index (CTDIvol) doses when using 16-cm vs. 32-cm phantoms. RESULTS There was relatively consistent phantom selection by body region. Overall, 98.0% of brain and skull examinations referenced 16-cm phantoms, and 95.7% of chest, 94.4% of abdomen and 100% of cervical-spine examinations referenced 32-cm phantoms. Only GE deviated from this practice, reporting chest and abdomen scans using 16-cm phantoms with some frequency in children up to 10 years of age. DLP and CTDIvol values from 16-cm phantom-referenced scans were 2-3 times higher than 32-cm phantom-referenced scans. CONCLUSION REFERENCE PHANTOM SELECTION IS HIGHLY CONSISTENT, WITH A SMALL BUT SIGNIFICANT NUMBER OF ABDOMEN AND CHEST SCANS (~5%) USING 16-CM PHANTOMS IN YOUNGER CHILDREN, WHICH PRODUCES DLP VALUES APPROXIMATELY TWICE AS HIGH AS EXAMS REFERENCED TO 32-CM PHANTOMS.
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Awe OO, Obed RI, Adekanmi AJ, Ogbole GI, Agbele AT. Thyroid dose and cancer risk from head and neck computed tomography at two selected centres in Nigeria. Niger Postgrad Med J 2021; 28:278-284. [PMID: 34850756 DOI: 10.4103/npmj.npmj_611_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Objective The objective of this study was to evaluate the thyroid glands' radiation dose and the risk of thyroid cancer induction from head or neck computed tomography (CT) examinations. Methods In a prospective study, we evaluated all participants of all ages and sex referred for Head or Neck CT Scan at the University College Hospital, Ibadan and Me Cure Healthcare Limited, Ibadan, Oyo State, Nigeria. Thyroid radiation dose was estimated with impact scan calculator, and real-time dose measurement with thermoluminescent badge dosimeters (TLDs). Data were analysed and P < 0.05 was considered statistically significant. Results One hundred and sixty-three participants (128 adults and 35 children) participated in the study. In most participants (74%), the tube voltage was 120 kVp. The estimated median thyroid gland dose by the imPACT scan calculator was 4.95 mGy (range = 1.20-30.0 mGy) and 4.40 mGy (range = 3.0-5.10 mGy), while the real-time dose measured by the TLD was 4.79 mGy (range = 1.73-96.7 mGy) and 2.33 mGy (range = 1.20-3.73 mGy) at Centre A and B, respectively. The estimated median thyroid cancer risk was 2.88 × 10-6 (maximum range of 52 × 10-6) at centre A and a median value of 3.20 × 10-6 with a cancer risk estimate that may reach 17.9 × 10-6 recorded at centre B, compared to a cumulative thyroid cancer risk of 0.12 × 10-5 among the general Nigerian population. Conclusions Scanner specifications and technique may significantly contribute to variations seen in thyroid radiation doses. There may be a need to optimise centre protocols and apply dose reference levels for head and neck CT examinations to reduce thyroid cancer risk in Nigeria.
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Affiliation(s)
- Olufisayo Olalekan Awe
- Department of Basic Sciences, Physics Electronics Unit, Babcock University, Ilishan-Remo; Department of Physics, University of Ibadan, Ibadan, Oyo State, Nigeria
| | | | | | - Godwin I Ogbole
- Department of Radiology, University College Teaching Hospital, Ibadan, Oyo State, Nigeria
| | - Alaba Tolulope Agbele
- Department of Basic Medical Sciences, College of Health Sciences and Technology, Ijero-Ekiti, Nigeria
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Abdulkadir MK, Piersson AD, Musa GM, Audu SA, Abubakar A, Muftaudeen B, Umana JE. Assessment of diagnostic reference levels awareness and knowledge amongst CT radiographers. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2021. [DOI: 10.1186/s43055-021-00444-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Reports indicated that numerous factors, including inadequate personnel knowledge, contributes to insufficient patient data for setting up diagnostic reference levels (DRLs) in developing countries. This study aims to evaluate the knowledge of DRLs as an optimisation tool amongst computed tomography (CT) radiographers in northern Nigeria. This is a quantitative cross-sectional study. A structured questionnaire was devised and distributed on site to sixty-two CT radiographers in northern Nigeria. A total of fifteen questions were included in the questionnaire focusing on DRLs, dose optimisation and dose descriptors generating quantitative data concerning overall CT radiographers’ perceived knowledge and awareness about DRLs.
Results
A response rate of 77.4% (48/62) was achieved. About 83.3% of the participants declare DRLs awareness, and 37.5% carried out a local dose survey. The percentage correctly perceived knowledge of concepts; DRLs was 45.8%, dose optimisation (42%) and CT dose descriptor (39%). Radiographers with work experience ranging from 4-10 years had the highest score.
Conclusion
In this survey, deficiencies were noted in radiographers’ knowledge about DRLs with precise knowledge gap in the implementation of local dose survey for DRLs and optimisation. There is a need for continuous radiographers’ training with greater emphasis on dose optimisation and institutional based dose evaluation.
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Feasibility of Ultra-High Resolution Supra-Aortic CT Angiography: An Assessment of Diagnostic Image Quality and Radiation Dose. Tomography 2021; 7:711-720. [PMID: 34842838 PMCID: PMC8628996 DOI: 10.3390/tomography7040059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
(1) Background: To evaluate diagnostic image quality and radiation exposure of ultra-high resolution cerebral Computed-Tomography (CT) angiography (CTA) obtained on an ultra-high resolution computed tomography scanner (UHR-CT). (2) Methods: Fifty consecutive patients with UHR-CTA were enrolled. Image reconstruction was processed with a 1024 × 1024 matrix and a slice thickness of 0.25 mm. Quantitative analyses comprising CT values, contrast-noise ratio (CNR) and signal-to-noise ratio (SNR) were performed. Subjective assessment of image quality, vessel contrast, noise, artefacts and delineation of different sized vessels were assessed by two readers on a 4-point scale. Radiation exposure was determined. (3) Results: Hounsfield values (ACI: 461.8 ± 16.8 HU; MCA: 406.1 ± 24.2 HU; BA: 412.2 ± 22.3 HU), SNR (ACI: 35.4 ± 13.1; MCA: 20.8 ± 12.4; BA: 23.7 ± 12.9) and CNR (ACI: 48.7 ± 21; MCA: 63.9 ± 26.9; BA: 48.1 ± 21.4) were remarkably high in all segments. Subjective analysis by two raters (fair agreement, k = 0.26) indicated excellent image qualities (image quality = 4; contrast = 4; noise = 3; artefacts = 4).Our analysis revealed a notably high traceability of the cerebral perforators (3 Points). Radiation exposure was at moderate dose levels (effective dose = 2.5 ± 0.6mSv). (4) Conclusions: UHR-CTA generates highly valuable image qualities that allow the depiction of vessels including cerebral perforators at acceptable dose levels. The UHR-CTA may therefore enhance the detection of small cerebral pathologies and may improve interpretability, especially in settings where high image qualities are crucial for the diagnostic accuracy.
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Bagherzadeh S, Jabbari N, Khalkhali HR. Radiation dose and cancer risks from radiation exposure during abdominopelvic computed tomography (CT) scans: comparison of diagnostic and radiotherapy treatment planning CT scans. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2021; 60:579-589. [PMID: 34542682 DOI: 10.1007/s00411-021-00942-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
In the present study, radiation doses and cancer risks resulting from abdominopelvic radiotherapy planning computed tomography (RP-CT) and abdominopelvic diagnostic CT (DG-CT) examinations are compared. Two groups of patients who underwent abdominopelvic CT scans with RP-CT (n = 50) and DG-CT (n = 50) voluntarily participated in this study. The two groups of patients had approximately similar demographic features including mass, height, body mass index, sex, and age. Radiation dose parameters included CTDIvol, dose-length product, scan length, effective tube current, and pitch factor, all taken from the CT scanner console. The ImPACT software was used to calculate the patient-specific radiation doses. The risks of cancer incidence and mortality were estimated based on the BEIR VII report of the US National Research Council. In the RP-CT group, the mean ± standard deviation of cancer incidence risk for all cancers, leukemia, and all solid cancers was 621.58 ± 214.76, 101.59 ± 27.15, and 516.60 ± 189.01 cancers per 100,000 individuals, respectively, for male patients. For female patients, the corresponding risks were 742.71 ± 292.35, 74.26 ± 20.26, and 667.03 ± 275.67 cancers per 100,000 individuals, respectively. In contrast, for DG-CT cancer incidence risks were 470.22 ± 170.07, 78.23 ± 18.22, and 390.25 ± 152.82 cancers per 100,000 individuals for male patients, while they were 638.65 ± 232.93, 62.14 ± 13.74, and 575.73 ± 221.21 cancers per 100,000 individuals for female patients. Cancer incidence and mortality risks were greater for RP-CT than for DG-CT scans. It is concluded that the various protocols of abdominopelvic CT scans, especially the RP-CT scans, should be optimized with respect to the radiation doses associated with these scans.
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Affiliation(s)
- Saeed Bagherzadeh
- Department of Medical Physics, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Nasrollah Jabbari
- Solid Tumor Research Center, Cellular and Molecular Medicine Institute, Urmia University of Medical Sciences, Urmia, Iran.
| | - Hamid Reza Khalkhali
- Patient Safety Research Center, Department of Biostatistics and Epidemiology, Urmia University of Medical Sciences, Urmia, Iran
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Karim M, Harun H, Kayun Z, Aljewaw O, Azizan S, Rafiz N, Muhammad N. Paediatric radiation dose and cancer risk associated with body effective diameter during CT thorax examination. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Nathan V, Prithishkumar IJ, Livingstone RS. Estimation of Anatomical Dimensions of the Thorax from Computed Tomography Images of the Adult and Pediatric Indian Population for Developing Optimal Radiological Protocols. J Med Phys 2021; 46:295-299. [PMID: 35261499 PMCID: PMC8853447 DOI: 10.4103/jmp.jmp_19_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 01/31/2021] [Accepted: 04/09/2021] [Indexed: 12/01/2022] Open
Abstract
Purpose: Ionizing radiation has been extensively used for medical diagnosis since its discovery in 1895; however, excessive use can lead to deleterious effects. Prior knowledge on radiological protocols based on simulations would be a practical tool for optimal use of radiation. Materials and Methods: Scan length of the thorax was measured from computed tomography (CT) topographic images and cross-sections at three levels of the thorax were measured from tomographic images of 500 adults and 340 children who had undergone CT thorax examinations using Centricity workstation software. The effective diameter (ED) of the thorax was calculated from anterio-posterior (AP) and transverse anatomical dimensions. Results: A 17% increase in scan length was observed for 6–10 years age group compared to 0–5 years, whereas there was marginal increase for 11–15 years of age. A 11.5% increase was observed for 16–18 years compared to 11-15 years age group. The cross-sectional phantom dimensions were calculated from ED measurements obtained from three regions of the thorax. Conclusions: This study has provided age- and gender-specific reference scan lengths, AP and transverse dimensions and ED for radiological examinations of the thorax. This information is useful to develop age- and gender-specific preset protocols and fabricate phantoms of the thorax for the pediatric and adult Indian population.
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Affiliation(s)
- Vandana Nathan
- Department of Anatomy, Karpagam Faculty of Medical Sciences and Research, Coimbatore, Tamil Nadu, India
| | - Ivan James Prithishkumar
- Department of Basic Sciences, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
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Kamo Y, Fujimoto S, Nozaki YO, Aoshima C, Kawaguchi YO, Dohi T, Kudo A, Takahashi D, Takamura K, Hiki M, Okai I, Okazaki S, Tomizawa N, Kumamaru KK, Aoki S, Minamino T. Incremental Diagnostic Value of CT Fractional Flow Reserve Using Subtraction Method in Patients with Severe Calcification: A Pilot Study. J Clin Med 2021; 10:jcm10194398. [PMID: 34640414 PMCID: PMC8509262 DOI: 10.3390/jcm10194398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 12/30/2022] Open
Abstract
Although on-site workstation-based CT fractional flow reserve (CT-FFR) is an emerging method for assessing vessel-specific ischemia in coronary artery disease, severe calcification is a significant factor affecting CT-FFR’s diagnostic performance. The subtraction method significantly improves the diagnostic value with respect to anatomic stenosis for patients with severe calcification in coronary CT angiography (CCTA). We evaluated the diagnostic capability of CT-FFR using the subtraction method (subtraction CT-FFR) in patients with severe calcification. This study included 32 patients with 45 lesions with severe calcification (Agatston score >400) who underwent both CCTA and subtraction CCTA using 320-row area detector CT and also received invasive FFR within 90 days. The diagnostic capabilities of CT-FFR and subtraction CT-FFR were compared. The sensitivities, specificities, positive predictive values (PPVs), and negative predictive values (NPVs) of CT-FFR vs. subtraction CT-FFR for detecting hemodynamically significant stenosis, defined as FFR ≤ 0.8, were 84.6% vs. 92.3%, 59.4% vs. 75.0%, 45.8% vs. 60.0%, and 90.5% vs. 96.0%, respectively. The area under the curve for subtraction CT-FFR was significantly higher than for CT-FFR (0.84 vs. 0.70) (p = 0.04). The inter-observer and intra-observer variabilities of subtraction CT-FFR were 0.76 and 0.75, respectively. In patients with severe calcification, subtraction CT-FFR had an incremental diagnostic value over CT-FFR, increasing the specificity and PPV while maintaining the sensitivity and NPV with high reproducibility.
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Affiliation(s)
- Yuki Kamo
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Shinichiro Fujimoto
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
- Correspondence: ; Tel.: +81-3-5802-1056
| | - Yui O. Nozaki
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Chihiro Aoshima
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Yuko O. Kawaguchi
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Tomotaka Dohi
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Ayako Kudo
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Daigo Takahashi
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Kazuhisa Takamura
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Makoto Hiki
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Iwao Okai
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Shinya Okazaki
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
| | - Nobuo Tomizawa
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (N.T.); (K.K.K.); (S.A.)
| | - Kanako K. Kumamaru
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (N.T.); (K.K.K.); (S.A.)
| | - Shigeki Aoki
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (N.T.); (K.K.K.); (S.A.)
| | - Tohru Minamino
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; (Y.K.); (Y.O.N.); (C.A.); (Y.O.K.); (T.D.); (A.K.); (D.T.); (K.T.); (M.H.); (I.O.); (S.O.); (T.M.)
- Japan Agency for Medical Research and Development-Core Research for Evolutionary Medical Science and Technology (AMED-CREST), Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
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Zamani H, Kavousi N, Masjedi H, Omidi R, Rahbar S, Perota G, Razavi E, Zare MH, Abedi-Firouzjah R. ESTIMATION OF DIAGNOSTIC REFERENCE LEVELS AND ACHIEVABLE DOSES FOR PEDIATRIC PATIENTS IN COMMON COMPUTED TOMOGRAPHY EXAMINATIONS: A MULTI-CENTER STUDY. RADIATION PROTECTION DOSIMETRY 2021; 194:214-222. [PMID: 34244802 DOI: 10.1093/rpd/ncab093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 05/06/2021] [Accepted: 06/02/2021] [Indexed: 06/13/2023]
Abstract
This study was conducted to determine first local diagnostic reference levels (DRLs) and achievable doses (ADs) for pediatric patients during the most common computed tomography (CT) procedures in Yazd province. The DRL was obtained based on volume CT dose index (CTDIvol) and dose length product (DLP) for four various age groups of children. Data were collected from the most commonly performed pediatric CT scans, including abdomen-pelvis, chest, brain and sinus examinations, at six high-loaded institutes. The patients' data (766 no.) in terms of CTDIvol and DLP were obtained from four age groups: ≤1-, 1-5-, 5-10- and 10-15-y-old. The 75th percentiles of CTDIvol and DLP were considered as DRL values and the 50th percentiles were described as ADs for those parameters. Consequently, the acquired DRLs were compared with other national and international published values. The DRLs in terms of CTDIvol for abdomen-pelvis, chest, brain and sinus examinations were 3, 8, 9 and 10 mGy; 4, 5, 5 and 5 mGy; 25, 28, 29 and 38 mGy; and 23, 24, 26 and 27 mGy for four different age groups of ≤1-, 1-5-, 5-10- and 10-15-y-old, respectively. The DRL values in terms of DLP were 75, 302, 321 and 342 mGy.cm; 109, 112, 135 and 170 mGy.cm, 352, 355, 360 and 481 mGy.cm; and 206, 211, 228 and 245 mGy.cm, respectively, for the mentioned age groups. In this study, the DRL and AD values in the brain examination were greater among the other studied regions. The DRL plays a critical role in the optimization of radiation doses delivered to patients and in improving their protection. This study provides the local DRLs and ADs for the most common pediatric CT scanning in Yazd province to create optimum situation for the clinical practice.
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Affiliation(s)
- Hamed Zamani
- Department of Medical Physics, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd 8915173160, Iran
| | - Nasim Kavousi
- Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hamidreza Masjedi
- Department of Medical Physics, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd 8915173160, Iran
| | - Reza Omidi
- Department of Medical Physics, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd 8915173160, Iran
| | - Shiva Rahbar
- Department of Medical Physics, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd 8915173160, Iran
| | - Ghazale Perota
- Department of Medical Physics, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd 8915173160, Iran
| | | | - Mohammad Hosein Zare
- Department of Medical Physics, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd 8915173160, Iran
- Clinical Research Development Center of Shahid Sadoughi hospital, Shahid Sadoughi University of Medical Sciences, Yazd 8915173160, Iran
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Tabesh J, Mahdavi M, Haddadi G, Ravanfar Haghighi R, Jalli R. Determination of Diagnostic Reference Level (DRL) in Common Computed Tomography Examinations with the Modified Quality Control-Based Dose Survey Method in Four University Centers: A Comparison of Methods. J Biomed Phys Eng 2021; 11:447-458. [PMID: 34458192 PMCID: PMC8385214 DOI: 10.31661/jbpe.v0i0.2105-1322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 06/20/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND The diagnostic reference level (DRL) is measured with different methods in the common Computed tomography (CT) exams, but it has not been measured through the size-specific dose estimate (SSDE) method in Iran, yet. OBJECTIVE This study aimed to calculate the local DRL (LDRL) using the new quality control-based dose survey method (QC) and patients' effective diameter (MQC) and compare them with a data collection method (DC) as well as local national DRLs (NDRL). MATERIAL AND METHODS In this cross-sectional study, LDRL, based on the third quartile of volumetric computed tomography dose index (CTDIvol) and dose length product (DLP) values, was calculated for the four common CT examinations in four CT scan centers affiliated with Shiraz University of Medical Sciences by DC, QC and MQC methods. The CTDIvol of each patient for each CT exam calculated with three methods was compared with paired t-test. Also, the LDRL using MQC method was compared with other national DRL studies. RESULTS There was a significant difference between the CTDIvol values calculated with MQC and QC in all four examinations (P <0.001). The LDRL based on CTDIvol obtained by the MQC method for head, sinus, chest, abdomen, and pelvis were (50, 18, 15, 19) mGy, respectively, and the calculated DLP values were also (735, 232, 519, 984) mGy.cm. CONCLUSION In MQC, LDRL based on CTDIvol was calculated with a mean difference percentage of (19.2 ± 11.6)% and (27.1 ± 8.1)% as compared to the QC and DC methods, respectively. This difference resulted from the use of the SSDE method and dose accuracy in the QC dose survey.
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Affiliation(s)
- Jalal Tabesh
- MSc, Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Maziyar Mahdavi
- PhD, Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
- PhD, Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Gholamhasan Haddadi
- PhD, Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
- PhD, Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Reza Jalli
- MD, Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Sookpeng S, Martin CJ, Butdee C. The investigation of dose and image quality of chest computed tomography using different combinations of noise index and adaptive statistic iterative reconstruction level. Indian J Radiol Imaging 2021; 29:53-60. [PMID: 31000942 PMCID: PMC6467048 DOI: 10.4103/ijri.ijri_124_18] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Background Computed tomography (CT) automatic tube current modulation (ATCM) systems and iterative reconstruction (IR) play an important role in CT radiation dose optimization. How the two can best be used together is one of the challenges faced by radiology professionals. Aim To determine optimum settings of ATCM noise index (NI) together with adaptive statistic iterative reconstruction (ASIR) for a general electric (GE) scanner that aims to achieve similar image quality to the standard protocol used in the hospital (Smart mA technique with NI of 11.57 and 30% ASIR reconstruction) with a lower dose. Methods Different NI and ASIR levels were set for scans of a phantom. Objective image quality assessments in terms of noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), low-contrast detectability (LCD), and modulation transfer function (MTF) were carried out in an anthropomorphic chest and a Catphan 700 phantom. Subjective image quality assessment was also performed with five readers to confirm whether the image quality of the new protocols was adequate. Result and Conclusion SNR and CNR increased with the strength of ASIR, and decreased with higher NI settings. The MTF improved slightly for higher dose levels and from filtered back projection (FBP) to higher strength of ASIR. LCD improved with ASIR compared to FBP and with higher strengths of ASIR. Qualitative scoring ranged between 3.0 and 4.6. A moderate degree of reliability was found between scoring. Use of NI 15.04 with 70% ASIR can reduce dose by 41% compared to the standard protocol of NI 11.57 with 30% ASIR without degradation of image quality.
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Affiliation(s)
- Supawitoo Sookpeng
- Department of Radiological Technology, Faculty of Allied Health Sciences, Naresuan University, Phitsanulok, Thailand
| | - Colin J Martin
- Department of Clinical Physics, University of Glasgow, Glasgow, UK
| | - Chitsanupong Butdee
- Department of Radiological Technology, Faculty of Allied Health Sciences, Naresuan University, Phitsanulok, Thailand
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Moghadam N, Rehani MM, Nassiri MA. Assessment of patients' cumulative doses in one year and collective dose to population through CT examinations. Eur J Radiol 2021; 142:109871. [PMID: 34332245 DOI: 10.1016/j.ejrad.2021.109871] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/30/2021] [Accepted: 07/16/2021] [Indexed: 01/14/2023]
Abstract
PURPOSE To estimate percentage of patients undergoing multiple CT exams leading to cumulative effective dose (CED) of more than 25, 50, 75 and 100 mSv in one year and assess per capita and the collective effective dose. METHODS Data from a regional hospital network was collected retrospectively using radiation dose monitoring system at 6 facilities with 8 CT scanners. The data was analyzed to find number of patients in different dose groups, their age, gender, number of CT exams and exams needed to reach 100 mSv based on age groups. RESULTS In one year 43,010 patients underwent 75,252 CT examinations. The number of exams per 1000 population was 153. Further 27% of the patients were younger than 55- years and 15.9% of them were younger than 45-year-old. A total of 0.67% of patients received a CED > 100 mSv; 3.5% had CED > 50 mSv, 11.9% with CED > 25 mSv and the maximum CED was 529 mSv. The minimum time to reach 100 mSv was a single CT exam. Seven patients received > 100 mSv in a single CT exam. 0.36% of patients had 10 or more CT exams in one year and 3.8% had 5 or more CT exams. The mean CED was 12.3 mSv, the average individual effective dose was 1.1 mSv and the collective effective dose was 521.3 person-Sv. CONCLUSIONS The alarming high CED received by large number of patients and with high collective dose to population requires urgent actions by all stake holders in the best interest of patient radiation safety.
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Affiliation(s)
- Narjes Moghadam
- Centre de recherche du Centre hospitalier universitaire de Sherbrooke (CRCHUS), Sherbrooke, Québec, Canada; Centre intégré universitaire de santé et de services sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke (CIUSSS de l'Estrie - CHUS), Sherbrooke, Québec, Canada.
| | - Madan M Rehani
- Radiology Department, Massachusetts General Hospital, Boston, MA, USA
| | - Moulay Ali Nassiri
- Centre de recherche du Centre hospitalier universitaire de Sherbrooke (CRCHUS), Sherbrooke, Québec, Canada; Centre intégré universitaire de santé et de services sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke (CIUSSS de l'Estrie - CHUS), Sherbrooke, Québec, Canada; Department of Nuclear Medicine and Radiobiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Canada
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Kinoshita M, Tanabe Y, Yoshida K, Kurata A, Kobayashi Y, Uetani T, Inoue K, Nishimura K, Ikeda S, Mochizuki T, Kido T, Yamaguchi O. Left ventricular longitudinal strain is a major determinant of CT-derived three-dimensional maximum principal strain: comparison with two-dimensional speckle tracking echocardiography. Heart Vessels 2021; 37:31-39. [PMID: 34232385 DOI: 10.1007/s00380-021-01901-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 07/02/2021] [Indexed: 11/24/2022]
Abstract
Computed tomography (CT)-derived three-dimensional maximum principal strain (MP-strain) can provide incremental value to coronary CT angiography for cardiac dysfunction assessment with high diagnostic performance in patients with myocardial infarction. Global longitudinal strain (GLS) measured using two-dimensional speckle tracking echocardiography (2D-STE) is more sensitive than left ventricular ejection fraction (LVEF) for detecting early myocardial dysfunction. We aimed to compare CT-derived MP-strain with each of 2D-STE-derived strains (i.e., longitudinal, circumferential, and radial strains), and identify the major determinants of CT-derived MP-strain among 2D-STE-derived strains. We studied 51 patients who underwent cardiac CT and echocardiography. CT images were reconstructed at every 5% (0-95%) of the RR interval. A dedicated workstation was used to analyze CT-derived MP-strain on the 16-segment model. We calculated CT-derived global MP-strain with all the 16 segments on a per patient basis. Pearson's test was used to assess correlations between CT-derived MP-strain and STE-strain at global and segmental levels. The intra-class correlation coefficient for interobserver agreement for CT-derived global MP-strain was 0.98 (95% confidence interval 0.96-0.99). The low-CT-derived global MP-strain group (≤ 0.43) had more patients with LV dysfunction than the high-CT-derived global MP-strain group (> 0.43). CT-derived global MP-strain was associated with STE-GLS (r = 0.738, P < 0.001), global circumferential strain (r = 0.646, P < 0.001), and global radial strain (r = 0.432, P = 0.001). In multivariate analysis, STE-GLS had the strongest association to CT-derived global MP-strain among three directional STE-strains and LVEF by echocardiography (standardized coefficient = - 0.527, P < 0.001). STE-GLS is a major determinant of CT-derived global MP-strain. CT-derived MP-strain may enhance the value of coronary CT angiography by adding functional information to CT-derived LVEF.
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Affiliation(s)
- Masaki Kinoshita
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
| | - Yuki Tanabe
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Kazuki Yoshida
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Akira Kurata
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Yusuke Kobayashi
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Teruyoshi Uetani
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Katsuji Inoue
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Kazuhisa Nishimura
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Shuntaro Ikeda
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Teruhito Mochizuki
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
- Department of Radiology, I.M. Sechenov First Moscow State Medical University, 19c1, Bol'shaya Pirogovskaya Ulitsa, Moscow, 119146, Russia
| | - Teruhito Kido
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Osamu Yamaguchi
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
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Tahmasebzadeh A, Paydar R, Soltani-Kermanshahi M, Maziar A, Reiazi R. Lifetime attributable cancer risk related to prevalent CT scan procedures in pediatric medical imaging centers. Int J Radiat Biol 2021; 97:1282-1288. [PMID: 34096826 DOI: 10.1080/09553002.2021.1931527] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE Evaluation of the organ dose in pediatric patients up to 15 years old and Estimation of lifetime attributable risk (LAR) of cancer incidence in pediatric computed tomography procedures. MATERIALS AND METHODS Data from 532 patients below 15 years old was collected and they were categorized into four age groups of <1, 1-5, 5-10, and 10-15 years old. NCICT software was used to calculate the organ dose, and LAR of cancer incidence has been estimated according to the BEIR VII report. RESULTS The highest median dose in all age groups was related to eye lens (head scan), thyroid (chest scan), and colon (abdomen-pelvic scan). The highest average LAR of cancer incidence was observed for breast cancer and colon cancer following a chest CT scan of the youngest group (<1-year-olds) [68.23 per 100,000] and abdomen-pelvic scans of the oldest group (10- to 15-year-olds) [57.30 per 100,000]. CONCLUSION This study shows that the average LAR is higher in females and it decreases with age in both genders. Although CT scan has an indispensable application in diagnosis, the patient dose should be taken into account before any examination specifically in pediatric patients.
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Affiliation(s)
- Atefeh Tahmasebzadeh
- Student Research Committee, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Paydar
- Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran.,Department of Radiation Science, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mojtaba Soltani-Kermanshahi
- Social Determinants of Health Research Center, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Asghar Maziar
- Department of Radiation Science, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Reiazi
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
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Abdulkadir MK, Izge IY, Yunusa GH, Mohammed A, Osman ND. Evaluation of age-based radiation dose in paediatric patients received from head CT examination at a tertiary hospital, Nigeria. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pediatric SMA patients with complex spinal anatomy: Implementation and evaluation of a decision-tree algorithm for administration of nusinersen. Eur J Paediatr Neurol 2021; 31:92-101. [PMID: 33711792 DOI: 10.1016/j.ejpn.2021.02.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 11/23/2022]
Abstract
The approval of nusinersen for the treatment of spinal muscular atrophy (SMA) has significantly changed the natural history of the disease. Nevertheless, scoliosis secondary to axial muscle weakness occurs at some point in most of patients with SMA and a conventional posterior interlaminar approach for intrathecal administration of nusinersen can be particularly challenging to perform in patients with severe scoliosis and/or previous spine fusion surgeries. We developed a protocol for the administration of nusinersen in pediatric patients, which includes a decision-tree algorithm that categorizes patients according to the estimated technical difficulty for the intrathecal administration. Complex spine patients were defined as those with a Cobb angle greater than 50° and/or a history of spinal surgery, while the rest of patients were considered non-complex. Nusinersen was successfully administered through a conventional non-CT-guided lumbar puncture in all 14 non-complex spine patients (110 out of 110 procedures; 100%). The feasibility of the intrathecal injection in the 15 complex spine patients was assessed by 3D CT. Administration was considered unfeasible in 7 out of these 15 patients according to imaging. In the 8 complex spine patients in whom the administration was considered feasible, conventional non-CT-guided lumbar punctures were successful only in 19 out of 53 procedures (36%). The remaining 34 procedures (64%) were guided by CT scan, all successful. Our work demonstrates that a cut-off point of 50° in Cobb angle and history of spinal surgery can reliably be used to anticipate the need for CT guidance in nusinersen administration.
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Kapoor S, O'Dowd K, Hilis A, Quraishi N. The Nottingham radiation protocol for O-arm navigation in paediatric deformity patients: a feasibility study. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2021; 30:1920-1927. [PMID: 33611717 DOI: 10.1007/s00586-021-06762-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 12/14/2020] [Accepted: 02/02/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND O-arm assisted pedicle screw placement has been proven to be more accurate than free-hand technique. Radiation exposure remains the primary drawback. We determined the feasibility and safety of a reduced radiation protocol in paediatric patients undergoing scoliosis correction. METHODS A reduced radiation protocol for a medtronic O-arm navigational system was devised. 3D CT reconstructions of an anthropomorphic pelvic phantom indicated adequate image quality after reduction to 14% of current manufacturer default factors. A feasibility study to test the image quality was undertaken on four patients, one with syndromic and three with idiopathic scoliosis each receiving progressively reducing radiation exposure of 60%, 50%, 40% and 14% of what would have been delivered using the manufacturer default protocol. This represented 32% of the mayo clinic protocol. It was achieved by reducing the x-ray tube current to 10 mA while keeping the tube potential at 90 kVp. RESULTS A low dose O-arm protocol was able to generate adequate image quality while delivering as little as 14% (for lumbar region reconstructions) of the recommended protocol radiation dose. The total radiation dose delivered with this protocol was approximately 0.8 milliSieverts for a single spin. This effective dose represents < 1/3 of average UK and < 1/6 average US annual radiation exposure. There were no neurological or implant-related complications. CONCLUSIONS Our low dose O-arm radiation protocol significantly reduces the radiation exposure compared to the manufacturer recommended Mayo clinic protocol providing operational image quality to allow accurate screw placement in spinal deformity.
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Affiliation(s)
- Saurabh Kapoor
- Department of Spinal Surgery, Queen's Medical Center, 15 Chester House, Nottingham, NG3 5AW, United Kingdom.
| | - Kenneth O'Dowd
- Department of Medical Physics, Queen's Medical Center, Nottingham, United Kingdom
| | - Aaron Hilis
- Department of Spinal Surgery, Queen's Medical Center, 15 Chester House, Nottingham, NG3 5AW, United Kingdom
| | - Nasir Quraishi
- Department of Spinal Surgery, Queen's Medical Center, 15 Chester House, Nottingham, NG3 5AW, United Kingdom
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Kumar V, Tayal S, Ali A, Gandhi A. Assessment of Effective Dose Received in Various Computed Tomography Protocols and Factors Affecting It. Indian J Nucl Med 2021; 36:32-38. [PMID: 34040293 PMCID: PMC8130704 DOI: 10.4103/ijnm.ijnm_112_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 11/13/2022] Open
Abstract
PURPOSE OF STUDY The purpose of the study was to evaluate the effect of patient characteristics and equipment-related factors on the computed tomography (CT) dose received by patients from positron emission tomography-CT (PET-CT) using system-generated dose-length product (DLP) values and also to check the effective dose (ED) received from various CT protocols at our institute. MATERIALS AND METHODS This retrospective study included 78 adult patients who underwent F-18 fluorodeoxyglucose whole-body PET-CT and were divided into three groups based on the area of primary cancerous lesion. In Group A, we had 44 patients who underwent PET-CT (head-and-neck protocol), in Group B, we had 24 patients who underwent PET-CT (whole body with brain protocol), and in Group C, we had 10 patients who underwent PET-CT (pelvis protocol). All of the patients under the study are of South Asian ethnicity. A majority of patients 53.85% were males and remaining 46.15% were females. The product of conversion factor (k-coefficient), as described in "American Association of Physicists in Medicine Report No. 96" and DLP value generated by the scanner, was used to calculate the ED. Moreover, we also performed regression analysis to check relation between body weight, height, scan range, tube current, Volume computed tomography dose index (CTDIvol), DLP, and ED. RESULTS The regression analysis shows that scan range, patient height, weight, tube current, and DLP were significantly correlated with ED (P < 0.05 for all). Moreover, the DLP and conversion factor method estimated the ED from various groups. Patients under Group A (head-and-neck protocol), Group B (whole body with brain protocol), Group C (pelvis protocol) received an average ED of 22.45 mSv, 22.40 mSv, and 21.24 mSv, respectively. CONCLUSION ED from CT component of PET-CT can be assessed as the product of scanner-generated DLP and conversion factor for selected range. Moreover, body weight, scan range, and tube current had an independent significant effect on ED received from CT.
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Affiliation(s)
- Vikrant Kumar
- Department of Nuclear Medicine, Kailash Cancer Hospital and Research Centre, Muni Seva Ashram, Vadodara, Gujarat, India
| | - Sachin Tayal
- Department of Nuclear Medicine, Kailash Cancer Hospital and Research Centre, Muni Seva Ashram, Vadodara, Gujarat, India
| | - Abbas Ali
- Department of Nuclear Medicine, Kailash Cancer Hospital and Research Centre, Muni Seva Ashram, Vadodara, Gujarat, India
| | - Arun Gandhi
- Department of Nuclear Medicine, Kailash Cancer Hospital and Research Centre, Muni Seva Ashram, Vadodara, Gujarat, India
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Tahmasebzadeh A, Paydar R, Soltani Kermanshahi M, Maziar A, Rezaei M, Reiazi R. PEDIATRIC REGIONAL DRL ASSESSMENT IN COMMON CT EXAMINATIONS FOR MEDICAL EXPOSURE OPTIMIZATION IN TEHRAN, IRAN. RADIATION PROTECTION DOSIMETRY 2020; 192:341-349. [PMID: 33338233 DOI: 10.1093/rpd/ncaa192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 10/09/2020] [Accepted: 10/27/2020] [Indexed: 06/12/2023]
Abstract
The main purpose of this pilot study was to assess the regional diagnostic reference level (RDRL) of computed tomography (CT) examinations to optimise medical exposure in five pediatric medical imaging centers in Tehran, Iran where the most frequent CT examinations were investigated. For each patient, CT volume dose indexes (CTDIvol) and dose length product (DLP) in each group were recorded and their third quartile was calculated and set as RDRL. Pediatrics were divided into four age groups (<1; 1-5; 5-10 and 10-15 years). Then, the third quartile values for head, chest and abdomen-pelvic CTs were, respectively, calculated for each group in terms of CTDIvol: 21.3, 24.4, 24.2 and 36.3 mGy; 2.9, 3.2, 3.7 and 5.7 mGy; 3.7, 5.7, 6.3 and 6.8 mGy; and in terms of DLP: 322.2, 390.1, 424.9 and 694.1 mGy.cm; 53.1, 115.2, 145.3 and 167.6 mGy.cm and 128.7, 317.7, 460.2 and 813.8 mGy.cm. Finally, RDRLs were compared with other countries and preceding data in Iran. As a result, CTDIVOL values were lower than other national and international studies except for chest and abdomen-pelvic values obtained in Europe. Moreover, this matter applied to DLP so that other formerly reported values were higher than the present study but European values for chest and abdomen-pelvic scans and also Tehran studies conducted in 2012. Variation of scan parameters (tube voltage (kVp), tube current (mAs) and scan length), CTDIvol and DLP of different procedures among different age groups were statistically significant (P-value < 0.05). The variations in dose between CT departments as well as between identical scanners suggest a large potential for optimization of examinations relative to which this study provides helpful data.
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Affiliation(s)
- Atefeh Tahmasebzadeh
- Research Committee, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Paydar
- Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran
- Radiation Science Department, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mojtaba Soltani Kermanshahi
- Social Determinants of Health Research Center, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Asghar Maziar
- Radiation Science Department, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mehdi Rezaei
- Department of Orthopedic, Tehran University of Medical Science, Tehran, Iran
| | - Reza Reiazi
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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