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Optimization of smoothing factor for fast non-local means algorithm in high pitch based low-dose computed tomography images with tin-filter. Radiat Phys Chem Oxf Engl 1993 2023. [DOI: 10.1016/j.radphyschem.2023.110762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Alsleem H, Tajaldeen A, Almutairi A, Almohiy H, Aldaais E, Albattat R, Alsleem M, Abuelhia E, Kheiralla OAM, Alqahtani A, Alghamdi S, Aljondi R, Alharbi R. The Actual Role of Iterative Reconstruction Algorithm Methods in Several Saudi Hospitals As A Tool For Radiation Dose Minimization of Ct Scan Examinations. J Multidiscip Healthc 2022; 15:1747-1757. [PMID: 36016857 PMCID: PMC9398457 DOI: 10.2147/jmdh.s376729] [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: 06/13/2022] [Accepted: 08/09/2022] [Indexed: 11/25/2022] Open
Abstract
Background Iterative reconstruction algorithm (IR) techniques were developed to maintain a lower radiation dose for patients as much as possible while achieving the required image quality and medical benefits. The main purpose of the current research was to assess the level and usage extent of IR techniques in computed tomographic (CT) scan exams. Also, the obligation of practitioners in several hospitals in Saudi Arabia to implement IR in CT exams was assessed. Material and Methodology The recent research was based on two studies: data collection and a survey study. Data on the CT scan examinations were retrospectively collected from CT scanners. The survey was conducted using a questionnaire to evaluate radiographers’ and radiologists’ perceptions about IR and their practices with IR techniques. The statistical analysis results were performed to measure the usage strength level of IR methods. Results and Discussions The IR strength level of 50% was selected for nearly 80% of different CT examinations and patients of different ages and weights. About 46% of the participants had not learned about IR methods during their college studies, and 54% had not received formal training in applying IR techniques. Only 32% of the participants had adequate experience with IR. Half of the participants were not involved in the updating process of the CT protocol. Conclusion The results indicate that the majority of radiographer and radiologist at four different hospitals in Saudi Arabia have no explicit or understandable knowledge of selecting IR strength levels during the CT examination of patients. There is a need for more training in IR applications for both radiologists and radiographers. Training sessions were suggested to support radiographers and radiologists to efficiently utilize IR techniques to optimize image quality. Further studies are required to adjust CT exam protocols effectively to utilize the IR technique.
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Affiliation(s)
- Haney Alsleem
- Department of Radiological Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Abdulrahman Tajaldeen
- Department of Radiological Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | | | - Hussain Almohiy
- Radiological Sciences, King Khalid University, Abha, Saudi Arabia
| | - Ebtisam Aldaais
- Department of Radiological Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Rayan Albattat
- Medical Imaging Department, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | - Mousa Alsleem
- College of Dentistry, King Faisal University, Alahsa, Saudi Arabia
| | - Elfatih Abuelhia
- Department of Radiological Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | | | - Ahmed Alqahtani
- Radiology Department, King Saud Medical City, Riyadh, Saudi Arabia
| | - Salem Alghamdi
- Department of Applied Radiologic Technology, University of Jeddah, Jeddah, Saudi Arabia
| | - Rowa Aljondi
- Department of Applied Radiologic Technology, University of Jeddah, Jeddah, Saudi Arabia
| | - Renad Alharbi
- Department of Radiology, Specialized Medical Complex, Jeddah, Saudi Arabia
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Ji H, You SK, Lee JE, Lee SM, Cho HH, Ohm JY. Feasibility of Pediatric Low-Dose Facial CT Reconstructed with Filtered Back Projection Using Adequate Kernels. JOURNAL OF THE KOREAN SOCIETY OF RADIOLOGY 2022; 83:669-679. [PMID: 36238515 PMCID: PMC9514522 DOI: 10.3348/jksr.2021.0003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/04/2021] [Accepted: 06/30/2021] [Indexed: 11/15/2022]
Abstract
Purpose Materials and Methods Results Conclusion
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Affiliation(s)
- Hye Ji
- Department of Radiology, Chungnam National University Hospital, Daejeon, Korea
| | - Sun Kyoung You
- Department of Radiology, Chungnam National University Hospital, Chungnam National University College of Medicine, Daejeon, Korea
| | - Jeong Eun Lee
- Department of Radiology, Chungnam National University Hospital, Chungnam National University College of Medicine, Daejeon, Korea
| | - So Mi Lee
- Department of Radiology, School of Medicine, Kyungpook National University, Kyungpook National University Chilgok Hospital, Daegu, Korea
| | - Hyun-Hae Cho
- Department of Radiology, Ewha Womans University Mokdong Hospital, Seoul, Korea
| | - Joon Young Ohm
- Department of Radiology, Chungnam National University Hospital, Daejeon, Korea
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Villemure-Poliquin N, Chrétien M, Leclerc JE. Navigation and non-navigation CT scan of the sinuses: comparison of the effective doses of radiation in children and adults. J Otolaryngol Head Neck Surg 2021; 50:66. [PMID: 34798901 PMCID: PMC8605512 DOI: 10.1186/s40463-021-00541-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: 01/16/2021] [Accepted: 09/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The advent of 3D navigation imaging has opened new borders to the endoscopic surgical approaches of naso-sinusal inflammatory and neoplastic disease. This technology has gained in popularity among otolaryngologists for endoscopic sinus and skull base surgeries in both adults and children. However, the increased tissue radiation required for data acquisition associated with 3D navigation protocols CT scans is a source of concern because of its potential health hazards. We aimed to compare the effective doses of radiation between 3D navigation protocols and standard protocols for sinus computed tomography (CT) scans for both the adult and pediatric population. METHODS We performed a retrospective cohort study through electronic chart review of patients undergoing sinus CT scans (standard and 3D navigation protocols) from May 2019 to December 2019 using a Siemens Drive (VA62A) CT scanner. The effective dose of radiation was calculated in mSv for all exams. Average irradiation doses were compared using a Student's T-Test or a Kruskall-Wallis test when appropriate. RESULTS A total of 115 CT scans were selected for analysis, of which 47 were standard protocols and 68 were 3D navigation protocols CT scans. Among these, 31 exams were performed on children and 84 exams on adults. For the total population, mean effective dose in the non-navigation CT scans was 0.37 mSv (SD: 0.16, N = 47) and mean effective dose in the 3D navigation sinus CT group was 2.33 mSv (SD: 0.45, N = 68). The mean difference between the two groups was statistically significant 1.97 mSv (CI 95% - 2.1 to - 1.83; P < 0.0001). There was a sixfold increase in radiation with utilization of 3D navigation protocols. The ratio was identical when the pediatric as well as the adult subset of patients were analyzed. CONCLUSION In our center, utilization of 3D navigation sinus CT protocols significantly increases radiation exposure. Otolaryngologists should be aware of this significant increase and should attempt to decrease the radiation exposure of their patients by limiting unnecessary scan orders and by evaluating 3D acquisition protocols locally with radiation physicists. LEVEL OF EVIDENCE Level IV.
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Affiliation(s)
- Noémie Villemure-Poliquin
- Département d'ophtalmologie et d'oto-rhino-laryngologie - chirurgie cervico-faciale, Faculté de Médecine, Université Laval, Québec, QC, Canada.
| | - Mario Chrétien
- Service de Physique Médicale et de Radioprotection, CHU de Québec - Université Laval, Pavillon Enfant-Jésus, 1401 18e Rue, Québec, G1J 1Z4, Canada
| | - Jacques E Leclerc
- Département d'ophtalmologie et d'oto-rhino-laryngologie - chirurgie cervico-faciale, Faculté de Médecine, Université Laval, Québec, QC, Canada
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Potential of dosage reduction of cone-beam CT dacryocystography in healthy volunteers by decreasing tube current. Jpn J Radiol 2020; 39:233-239. [PMID: 33106970 DOI: 10.1007/s11604-020-01058-5] [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: 09/26/2020] [Accepted: 10/12/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE Cone-beam CT dacryocystography (CBCT-DCG) is a newly developed lacrimal passage imaging technique. This pilot study aimed to determine the effect of reducing tube current on image quality and radiation dose of CBCT-DCG in healthy volunteers. MATERIALS AND METHODS Thirty volunteers were randomly divided into three groups of ten. Each group of subjects underwent CBCT-DCG using a tube current of 13 mA, 10 mA, and 7 mA respectively. The image quality of CBCT-DCG was assessed independently by two observers using three different scoring methods and compared among the groups. The effective dose was estimated and compared among the three different tube current groups. RESULTS The CBCT-DCG images provided a high spatial and contrast resolution of the bony structures and the contrast medium. No significant differences were found in the image quality between different tube current groups. Compared with the 13 mA group (49.44 μSv), the effective dose for 10 mA group (38.40 μSv) and 7 mA group (27.12 μSv) decreased by 22.33% and 45.15%, respectively. CONCLUSION By decreasing the tube current, CBCT-DCG can be performed with a significant reduction of effective dose without loss of image quality in healthy volunteers.
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Diklić A, Valković Zujić P, Šegota D, Dundara Debeljuh D, Jurković S, Brambilla M, Kalra MK. Optimization of paranasal sinus CT procedure: Ultra-low dose CT as a roadmap for pre-functional endoscopic sinus surgery. Phys Med 2020; 78:195-200. [PMID: 33038645 DOI: 10.1016/j.ejmp.2020.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/14/2020] [Accepted: 09/19/2020] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVE To assess image quality and radiation dose associated with ultra-low dose CT protocol for patients with benign paranasal sinus diseases undergoing functional endoscopic surgery (FESS). METHODS We scanned the head portion of Alderson RANDO phantom on a second generation, dual-source, multidetector-row CT scanner (Siemens Definition Flash) using standard-dose and five low-dose protocols. Two radiologists assessed the image quality for each protocol to determine best ultra-low-dose protocols for imaging patients with benign paranasal sinus diseases undergoing FESS. The ultra-low-dose CT protocols were then used for scanning. Thereafter, 40 adult patients (age range 18-54 years, M:F 23:17) were scanned with the four low dose scanning protocols (10 patients per protocol). On both transverse and coronal reformatted CT images, two radiologists assessed visibility of key anatomic landmarks for FESS on a 2-point scale (1 = clear and complete visualization; 2 = suboptimal visualization). Data were analyzed with descriptive statistics and Cohen's kappa coefficient for interobserver agreement. RESULTS In phantom study, the lowest dose scan protocol (CTDIvol 2.1 mGy, 70 kV, 75 mAs) was unacceptable due to poor image quality. For patient studies, both radiologists gave acceptable image quality scores for ultra-low-dose scan protocol with axial scan mode, automatic tube potential selection and tube current modulation (CTDIvol 2.2 mGy; DLP 22.9 mGy.cm) with up to 60% lower dose compared to prior standard-dose CT (CTDIvol 5.3 mGy; DLP 73.5 mGy.cm). CONCLUSIONS Ultra-low-dose CT protocol provides sufficient image quality for scanning patients undergoing functional endoscopic surgery for benign paranasal sinus diseases.
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Affiliation(s)
- Ana Diklić
- Medical Physics and Radiation Protection Department, University Hospital Rijeka, Krešimirova 42, Rijeka, Croatia; Medical Physics and Biophysics Department, Medical Faculty, University of Rijeka, Braće Branchetta 20, Rijeka, Croatia.
| | - Petra Valković Zujić
- Radiology Department, University Hospital Rijeka, Krešimirova 42, Rijeka, Croatia; Radiology Department, Medical Faculty, University of Rijeka, Braće Branchetta 20, Rijeka, Croatia
| | - Doris Šegota
- Medical Physics and Radiation Protection Department, University Hospital Rijeka, Krešimirova 42, Rijeka, Croatia
| | - Dea Dundara Debeljuh
- Medical Physics and Radiation Protection Department, University Hospital Rijeka, Krešimirova 42, Rijeka, Croatia; Radiology Department, General Hospital Pula, Santoriova 24a, Pula, Croatia
| | - Slaven Jurković
- Medical Physics and Radiation Protection Department, University Hospital Rijeka, Krešimirova 42, Rijeka, Croatia; Medical Physics and Biophysics Department, Medical Faculty, University of Rijeka, Braće Branchetta 20, Rijeka, Croatia
| | - Marco Brambilla
- Department of Medical Physics, Azienda Ospedaliero Universitaria Maggiore della Carità, Novara, Italy
| | - Mannudeep K Kalra
- Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
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Chi J, Ji YD, Shen L, Yin SN, Ding N, Chen XF, Xu DF. Low-dose CT of paediatric paranasal sinus using an ultra-low tube voltage (70 kVp) combined with the flash technique. Clin Radiol 2020; 76:77.e17-77.e21. [PMID: 32950256 DOI: 10.1016/j.crad.2020.08.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 08/20/2020] [Indexed: 10/23/2022]
Abstract
AIM To evaluate the radiation dose and diagnostic image quality of low-dose computed tomography (CT) of the paranasal sinus in children, with acquisition at an ultra-low tube voltage (70 kVp) combined with the Flash technique. MATERIALS AND METHODS Eighty paediatric patients underwent CT of the paranasal sinus and were divided into two groups according to different protocols (group A: 80 kVp protocol with conventional spiral mode [n=40] and group B: 70 kVp protocol with Flash scan mode [n=40]). For each examination, the CT dose index (CTDIvol), dose-length product (DLP), and effective dose (ED) were estimated. The image noise, signal-to-noise ratio (SNR), and overall subjective diagnostic image quality were also evaluated. RESULTS For radiation dose, the CTDIvol (mGy), DLP (mGy·cm), and ED (mSv) values of the 70 kVp protocol were significantly lower than those of the 80 kVp protocol (CTDIvol: 1.57±0.009 versus 0.39±0.004 mGy, p<0.001; DLP: 19.88±2.01 versus 6.31±0.52 mGy·cm, p<0.001; ED: 0.079±0.016 versus 0.024±0.005 mSv, p<0.001). Compared with those of the 80-kVp protocol, the image noise increased by 40.7% (p=0.113), the SNRsoft-tissue decreased by 48.9%, and the SNRbone increased by 10.1% with the 70-kVp protocol (p=0.176 and 0.227, respectively). There was no significant difference in the overall subjective image quality grades between these two groups (p=0.15). CONCLUSION When imaging the paranasal sinus in children, an ultra-low tube voltage (70 kVp) combined with the Flash CT technique can reduce the radiation dose significantly while maintaining diagnostic image quality with clinically acceptable image noise.
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Affiliation(s)
- J Chi
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - Y-D Ji
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - L Shen
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - S-N Yin
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - N Ding
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - X-F Chen
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - D-F Xu
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China.
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Chi J, Xu D, Yin S, Li M, Shen L, Ding N, Chen X, Ji Y. Reducing the radiation dose of pediatric paranasal sinus CT using an ultralow tube voltage (70 kVp) combined with iterative reconstruction: Feasibility and image quality. Medicine (Baltimore) 2020; 99:e21886. [PMID: 32846848 PMCID: PMC7447483 DOI: 10.1097/md.0000000000021886] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND As the gold standard for imaging sinus disease, the main disadvantage of computed tomography (CT) of the pediatric paranasal sinus is radiation exposure. Because of this, 1 protocol for CT should reduce radiation dose while maintaining image quality. The aim of this study is to evaluate the image quality of dose-reduced paranasal sinus computed tomography (CT) using an ultralow tube voltage (70 kVp) combined with iterative reconstruction (IR) in children. METHODS CT scans of the paranasal sinus were performed using different protocols [70 kVp protocols with IR, Group A, n = 80; 80 kVp protocols with a filtered back projection algorithm, Group B, n = 80] in 160 pediatric patients. Then, the volume-weighted CT dose index, dose-length product, and effective dose were estimated. Image noise, the signal-to-noise ratio and the diagnostic image quality were also evaluated. RESULTS For the radiation dose, the volume-weighted CT dose index, dose-length product and effective dose values were significantly lower for the 70 kVp protocols than for the 80 kVp protocols (P < .001). Compared with the 80 kVp protocols, the 70 kVp protocols had significantly higher levels of image noise (P = .001) and a lower signal-to-noise ratio (P = .002). No significant difference in the overall subjective image quality grades was observed between these 2 groups (P = .098). CONCLUSION The ultralow tube voltage (70 kVp) technique combined with IR enabled a significant dose reduction in CT examinations performed in the pediatric paranasal sinus while maintaining diagnostic image quality with clinically acceptable image noise.
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Chen PA, Chen CW, Chou CC, Fu JH, Wang PC, Hsu SH, Lai PH. Quantitative and qualitative evaluation of low-dose craniocervical computed tomography angiography with a lower tube voltage protocol. Acta Radiol 2019; 60:1380-1389. [PMID: 30732454 DOI: 10.1177/0284185119825488] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Po-An Chen
- Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung
| | - Chih-Wei Chen
- Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung
| | - Chiung-Chen Chou
- Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung
| | - Jui-Hsun Fu
- Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung
| | - Po-Chin Wang
- Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung
| | - Shuo-Hsiu Hsu
- Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung
| | - Ping-Hong Lai
- Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung
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Tin-filtered 100 kV ultra-low-dose CT of the paranasal sinus: Initial clinical results. PLoS One 2019; 14:e0216295. [PMID: 31059550 PMCID: PMC6502333 DOI: 10.1371/journal.pone.0216295] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 04/17/2019] [Indexed: 01/28/2023] Open
Abstract
Objectives To investigate the feasibility, diagnostic image quality and radiation dose of 3rd generation dual-source computed tomography (CT) using a tin-filtered 100 kV protocol in patients with suspected acute inflammatory sinus disease. Methods We retrospectively evaluated 109 consecutive patients who underwent CT (Siemens SOMATOM Force, Erlangen, Germany) of the paranasal sinus with a new tin-filtered scan-protocol (Sn100 kV; tube current 35 mAs) using iterative reconstruction. Two readers independently assessed subjective image quality using a five-point Likert scale (1 = excellent, 5 = non-diagnostic). Inter-observer agreement was calculated and expressed as percentage of agreement. Noise was determined for calculation of signal-to-noise-ratio (SNR). Effective radiation dose (ED) was calculated from the dose-length-product (DLP). Results All examinations showed diagnostic image quality regarding evaluation of inflammatory sinus disease. On average, subjective general image quality was rated moderate (= 3) with a percentage of agreement between the observers of 81%. The mean image noise was 14.3 HU. The calculated median SNR was 6.0 for intraorbital fat, and 3.6 for the vitreous body, respectively. The median DLP was 2.1 mGy*cm, resulting in a median ED of 0.012 mSv. Conclusions Taking the study limitations into account, ultra-low-dose tin-filtered CT of the paranasal sinus at a tube voltage of 100 kV utilizing an iterative reconstruction algorithm provides for reliable exclusion of suspected acute inflammatory sinus disease in 100% of the cases.
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Rawashdeh M, McEntee MF, Zaitoun M, Abdelrahman M, Brennan P, Alewaidat H, Lewis S, Saade C. Knowledge and practice of computed tomography exposure parameters amongst radiographers in Jordan. Comput Biol Med 2018; 102:132-137. [PMID: 30278337 DOI: 10.1016/j.compbiomed.2018.09.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 09/20/2018] [Accepted: 09/24/2018] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To investigate the knowledge and practice of computed tomography (CT) radiographers working in Jordan. MATERIALS AND METHODS This Institutional Review Board (IRB) approved study disseminated a questionnaire via social media and recruited 54 Jordanian CT radiographers. The questionnaire comprised 36 questions divided into four sections: demographics; an evaluation of knowledge regarding CT exposure; modifications to CT exposure for paediatric patients; dose units and diagnostic reference levels (DRLs). Descriptive and inferential statistics including Chi-square tests, Mann-Whitney U tests, independent samples t-tests and Kruskal-Wallis H tests were employed. Statistical significance was considered below p < 0.05. RESULTS The 54 participants had various qualifications, with the majority holding a Bachelor's degree (n = 35, 64.8%) and the rest holding a Diploma (n = 19, 35.2%). In order to pass the questionnaire, participants needed to score 13 correct answers. The overall number of radiographers who correctly passed the questionnaire was 48 (88.9%). None of the participants correctly stated all the DRL values for chest, abdomen and brain CT. However, four out of 54 respondents (7.4%) knew the chest DRL value, three (5.6%) participants correctly estimated the abdominal DRL value but only two (3.7%) knew the DRL for the brain. CONCLUSION Good general knowledge was found amongst radiographers regarding the relationship of each exposure parameter to the image quality and patient dose. However, there was poor knowledge of diagnostic reference levels and the order of the organ radiation sensitivity. The need for CT radiographers to undertake further education that focuses on radiation exposure in CT is highlighted.
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Affiliation(s)
- Mohammad Rawashdeh
- Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan.
| | - Mark F McEntee
- Medical Image Optimisation and Perception Group (MIOPeG), Brain and Mind Centre, Faculty of Health Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Maha Zaitoun
- Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Mostafa Abdelrahman
- Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Patrick Brennan
- Medical Image Optimisation and Perception Group (MIOPeG), Brain and Mind Centre, Faculty of Health Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Haytham Alewaidat
- Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Sarah Lewis
- Medical Image Optimisation and Perception Group (MIOPeG), Brain and Mind Centre, Faculty of Health Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Charbel Saade
- Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut, Lebanon
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Almashraqi AA, Ahmed EA, Mohamed NS, Barngkgei IH, Elsherbini NA, Halboub ES. Evaluation of different low-dose multidetector CT and cone beam CT protocols in maxillary sinus imaging: part I-an in vitro study. Dentomaxillofac Radiol 2017; 46:20160323. [PMID: 28266870 DOI: 10.1259/dmfr.20160323] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES This in vitro study aimed to assess radiation dose and image quality of different low-dose multidetector CT (MDCT) and CBCT imaging protocols in comparison with the standard MDCT protocol for maxillary sinus imaging. METHODS Effective dose (E) and image quality of 10 MDCT (changing effective milliampere second starting from 141.3 EmAs to 20 EmAs) and 3 CBCT protocols (changing milliampere second and voxel size) were assessed throughout scanning an anthropomorphic head and neck Alderson Rando phantom. E values were calculated using thermoluminescent dosemeters (TLDs) fixed at 6 sensitive organs (14 sites) on the Rando phantom. Image quality was assessed objectively (by calculating the standard deviation values of the radiographic density of water) and subjectively (by assessing the diagnostic image quality using a four-graded scale: 1 = very good, 2 = good, 3 = acceptable and 4 = unacceptable). RESULTS Two MDCT protocols (120 kV/32 EmA and 120 kV/25 EmA) had lower radiation doses with statistically significant differences (p < 0.001) compared with that of the standard MDCT protocol (120 kV/141.3 EmA), and they preserved a good diagnostic image quality. One CBCT protocol (120 kV/20 mA) had a reasonable radiation dose and good image quality. There were no statistically significant differences between the above-mentioned lower dose MDCT and CBCT protocols (p > 0.05) with respect to the radiation dose and image quality. CONCLUSIONS The low-dose MDCT and CBCT protocols are viable methods for maxillary sinus examination as evaluated using the above-mentioned phantom that yield a good diagnostic image quality using E approximately 7 and 11 times lower than that of the standard MDCT, respectively. These findings were evaluated in the in vivo part of this project.
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Affiliation(s)
- Abeer A Almashraqi
- 1 Department of Oral Radiology, Faculty of Dentistry, Ibb University, Ibb, Yemen.,2 Department of Maxillofacial Surgery and Diagnostic Sciences, College of Dentistry, Jazan University, Jazan, Saudi Arabia
| | - Eman A Ahmed
- 3 Department of Oral and Maxillofacial Radiology, College of Oral and Dental Medicine, Cairo University, Cairo, Egypt.,4 Department of Oral and Maxillofacial Radiology, Faculty of Oral and Dental Surgery, Misr University for Science and Technology, Giza, Egypt
| | - Nashwa S Mohamed
- 3 Department of Oral and Maxillofacial Radiology, College of Oral and Dental Medicine, Cairo University, Cairo, Egypt.,5 Department of Oral and Maxillofacial Radiology, Faculty of Oral and Dental Medicine, Misr International University, Cairo, Egypt
| | - Imad H Barngkgei
- 6 Department of Oral Medicine, Faculty of Dentistry, Damascus University, Damascus, Syria.,7 Department of Oral Medicine, Faculty of Dentistry, Syrian Private University, Damascus, Syria
| | - Nader A Elsherbini
- 8 Department of Medical Radiation Physics, Kasr Al-Aini Center of Oncology and Nuclear Medicine, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Esam S Halboub
- 2 Department of Maxillofacial Surgery and Diagnostic Sciences, College of Dentistry, Jazan University, Jazan, Saudi Arabia.,9 Department of Oral Medicine and Diagnosis, Faculty of Dentistry, Sana'a University, Sana'a, Yemen
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Koivisto J, van Eijnatten M, Järnstedt J, Holli-Helenius K, Dastidar P, Wolff J. Impact of prone, supine and oblique patient positioning on CBCT image quality, contrast-to-noise ratio and figure of merit value in the maxillofacial region. Dentomaxillofac Radiol 2017; 46:20160418. [PMID: 28306334 DOI: 10.1259/dmfr.20160418] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To assess the impact of supine, prone and oblique patient imaging positions on the image quality, contrast-to-noise ratio (CNR) and figure of merit (FOM) value in the maxillofacial region using a CBCT scanner. Furthermore, the CBCT supine images were compared with supine multislice CT (MSCT) images. METHODS One fresh frozen cadaver head was scanned in prone, supine and oblique imaging positions using a mobile CBCT scanner. MSCT images of the head were acquired in a supine position. Two radiologists graded the CBCT and MSCT images at ten different anatomical sites according to their image quality using a six-point scale. The CNR and FOM values were calculated at two different anatomical sites on the CBCT and MSCT images. RESULTS The best image quality was achieved in the prone imaging position for sinus, mandible and maxilla, followed by the supine and oblique imaging positions. 12-mA prone images presented high delineation scores for all anatomical landmarks, except for the ear region (carotid canal), which presented adequate to poor delineation scores for all studied head positions and exposure parameters. The MSCT scanner offered similar image qualities to the 7.5-mA supine images acquired using the mobile CBCT scanner. The prone imaging position offered the best CNR and FOM values on the mobile CBCT scanner. CONCLUSIONS Head positioning has an impact on CBCT image quality. The best CBCT image quality can be achieved using the prone and supine imaging positions. The oblique imaging position offers inadequate image quality except in the sinus region.
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Affiliation(s)
- Juha Koivisto
- 1 Department of Oral and Maxillofacial Surgery/Oral Pathology and 3D Innovation Lab, VU University Medical Center, Amsterdam, Netherlands
| | - Maureen van Eijnatten
- 1 Department of Oral and Maxillofacial Surgery/Oral Pathology and 3D Innovation Lab, VU University Medical Center, Amsterdam, Netherlands
| | - Jorma Järnstedt
- 2 Medical Imaging Center, Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Kirsi Holli-Helenius
- 2 Medical Imaging Center, Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Prasun Dastidar
- 2 Medical Imaging Center, Department of Radiology, Tampere University Hospital, Tampere, Finland.,3 University of Tampere, Medical School, Tampere, Finland
| | - Jan Wolff
- 1 Department of Oral and Maxillofacial Surgery/Oral Pathology and 3D Innovation Lab, VU University Medical Center, Amsterdam, Netherlands
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FALCINELLI CRISTINA, SCHILEO ENRICO, BARUFFALDI FABIO, CRISTOFOLINI LUCA, TADDEI FULVIA. THE EFFECT OF COMPUTED TOMOGRAPHY CURRENT REDUCTION ON PROXIMAL FEMUR SUBJECT-SPECIFIC FINITE ELEMENT MODELS. J MECH MED BIOL 2017. [DOI: 10.1142/s0219519417500129] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Many studies have addressed the modulation of computed tomography (CT) parameters, and particularly of tube current, to obtain a good compromise between the X-ray dose to the patient and the image quality for diagnostic applications. This study aimed at evaluating the influence of dose reduction by means of tube current reduction on the CT-based subject-specific finite element (FE) modeling. To this aim, CT scans at stepwise reduced values of tube current from 180[Formula: see text]mAs to 80[Formula: see text]mAs were performed on: (i) a densitometric phantom, to quantify the changes in the calibration equation; (ii) a fresh-frozen, water submersed, human cadaver femur, to quantify changes in geometry reconstruction and material mapping from CT, as well as strain prediction accuracy, based on the in vitro strain measurements available; (iii) a fresh-frozen human cadaver thigh with soft tissues attached, to quantify FE results changes in conditions similar to those found in vivo. The results showed that the tube current reduction does not affect the 3D modeling and the femur FE analysis. Our pilot study highlights the possibility of performing CT scans with reduced dose to generate biomechanical models, although a confirmation by performing larger studies with clinical CT data is needed.
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Affiliation(s)
- CRISTINA FALCINELLI
- Laboratorio di Bioingegneria Computazionale, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy
- Dipartimento di Ingegneria Civile, Università di Roma Tor Vergata, Via del Politecnico 1, 00133 Roma, Italy
| | - ENRICO SCHILEO
- Laboratorio di Bioingegneria Computazionale, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy
| | - FABIO BARUFFALDI
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy
| | - LUCA CRISTOFOLINI
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy
- Dipartimento di Ingegneria Industriale, Università di Bologna Viale Risorgimento 2, 40136 Bologna, Italy
| | - FULVIA TADDEI
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy
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Lin WC, Wang HH, Hsu WL, Cao BH, Chen DJ, Tsai CJ. Investigation of an optimized scanning protocol for the dentomaxillofacial region using 320-slice multidetector computed tomography. Dentomaxillofac Radiol 2017; 46:20160395. [PMID: 28128650 DOI: 10.1259/dmfr.20160395] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To propose an imaging protocol that provides satisfactory image quality for oral examination while minimizing radiation dosage using 320-slice multidetector CT (MDCT). METHODS An anthropomorphic head phantom was scanned using 320 MDCT with protocols combining different scanning modes: volume scanning (whole or local) vs helical scanning (80- or 64-slice detectors); tube voltage settings (80 kVp, 120 kVp and 135 kVp); and tube current settings (60 mA, 80 mA, 100 mA and 120 mA). A total of six anatomical bone structures and three anatomical soft-tissue structures were assessed using quantitative and qualitative analysis in the three orthographic planes (axial, sagittal and coronal). A figure of merit (FOM) was used to determine the optimal imaging protocol in terms of tube voltage, tube current and scanning mode. RESULTS The 80-kVp setting had the worst quantitative and qualitative results (both p < 0.001) compared with the 135-kVp and 120-kVp settings, especially for soft-tissue structures. A significant difference was noted for the scores obtained using a tube current between 120 mA and 60 mA by quantitative analysis, but not by qualitative analysis. Volume scans using either whole or local modes had a significantly higher FOM than helical scanning of 80 or 64 slices. CONCLUSIONS In 320 MDCT, a protocol using 135 kVp, 80 mA and the volume-scanning mode (whole or local) offers adequate visualization of both soft-tissue and bone structures while keeping the radiation dose as low as possible. This may therefore be considered a first choice among a wide selection of scanning protocols for dentomaxillofacial CT.
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Affiliation(s)
- Wei-Chan Lin
- 1 Department of Radiology, Cathay General Hospital, Taipei, Taiwan.,2 School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Hsueh-Han Wang
- 3 Department of Radiology, National Yang-Ming University Hospital, Yilan City, Taiwan
| | - Wen-Lin Hsu
- 4 School of Medicine, Tzu-Chi University, Hualien, Taiwan.,5 Department of Radiation Oncology, Buddhist Tzu-Chi General Hospital, Hualien, Taiwan
| | - Bi-Hui Cao
- 6 Department of Radiology, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - De-Ji Chen
- 6 Department of Radiology, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Chia-Jung Tsai
- 7 Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan
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Fraczek M, Guzinski M, Morawska-Kochman M, Nelke KH, Krecicki T. Nasal endoscopy: an adjunct to patient selection for preoperative low-dose CT examination in chronic rhinosinusitis. Dentomaxillofac Radiol 2016; 45:20160173. [PMID: 27635789 DOI: 10.1259/dmfr.20160173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The growing awareness of increased X-ray exposure to the public has led to the propagation of several methods for reducing the radiation dose during CT examination. Low-dose CT protocols do not, however, have an established role in pre-operative evaluation. The aim of this article was to assess the usefulness of nasal endoscopy in the selection of patients under pre-operative care for low-dose CT examination. METHODS A cadaver head was used to discover institutional minimum acceptable CT image quality and scanning settings. Then, 134 adult patients with chronic rhinosinusitis (CRS) were enrolled into the study and divided randomly into standard dose (120 kVp, 100 mAs) or low-dose CT groups (120 kVp, 45 mAs). Subjective assessment of the diagnostic image quality of the surgically relevant anatomical structures was compared using a five-point scale (from excellent to unacceptable) by a radiologist and sinus surgeon independently. Pathologic states of the nose were quantified according to the Lund-Kennedy endoscopic system (LKES) and Lildholdt's scale. RESULTS Image quality was similar in low-dose and standard dose groups in patients without polyps. The quality of 13% of scans from patients with polyps from the low-dose group and 4% from the standard dose group was in the range from moderate to poor. The quality of scans obtained with low milliamperes second (mAs) values worsened in patients with polyps in the middle meatus, but the difference was particularly pronounced compared with standard dose among subjects with Lildholdt's score above 2 (p < 0.001). Correlation with LKES revealed that changes other than polyps (i.e. discharge, oedema, scaring or crusting) in the nasal cavity alone do not affect the image quality. Interobserver agreement in both groups was very high. CONCLUSIONS Low-dose scanning should be promoted as the screening imaging method of choice in patients with suspected CRS. Furthermore, low mAs value examination can be performed pre-operatively without fear of significant image quality deterioration in uncomplicated CRS patients without polyps, or with minor changes in nasal endoscopy. Standard dose CT, which provides a better identification of bony landmarks, minimizes diagnostic errors and risk to patients, so it might be considered in those with polyps below the middle turbinate.
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Affiliation(s)
- Marcin Fraczek
- 1 Department of Otorhinolaryngology, Wroclaw Medical University, Wroclaw, Poland
| | - Maciej Guzinski
- 2 Department of Radiology, Wroclaw Medical University, Wroclaw, Poland
| | | | - Kamil H Nelke
- 3 Department of Maxillofacial Surgery, Wroclaw Medical University, Wroclaw, Poland
| | - Tomasz Krecicki
- 1 Department of Otorhinolaryngology, Wroclaw Medical University, Wroclaw, Poland
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Investigation of sinonasal anatomy via low-dose multidetector CT examination in chronic rhinosinusitis patients with higher risk for perioperative complications. Eur Arch Otorhinolaryngol 2016; 274:787-793. [PMID: 27554662 PMCID: PMC5281658 DOI: 10.1007/s00405-016-4268-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 08/13/2016] [Indexed: 10/28/2022]
Abstract
The aim of the study was to compare visualisation of the surgically relevant anatomical structures via low- and standard-dose multidetector CT protocol in patients with chronic rhinosinusitis (CRS) and higher risk for perioperative complications (i.e. presence of bronchial asthma, history of sinus surgery and advanced nasal polyposis). 135 adult CRS patients were divided randomly into standard-dose (120 kVp, 100 mAs) or low-dose CT groups (120 kVp, 45 mAs). The detectability of the vital anatomical structures (anterior ethmoid artery, optic nerve, cribriform plate and lamina papyracea) was scored using a five-point scale (from excellent to unacceptable) by a radiologist and sinus surgeon. Polyp sizes were quantified endoscopically according to the Lildholdt's scale (LS). Olfactory function was tested with the "Sniffin' Sticks" test. On the low-dose CT images, detectability ranged from 2.42 (better than poor) for cribriform plate among anosmic cases to 4.11 (better than good) for lamina papyracea in cases without nasal polyps. Identification of lamina papyracea on low-dose scans was significantly worse in each group and the same was the case with cribriform plates in patients with advanced polyposis and anosmia. Cribriform plates were the most poorly identified (between poor and average) among all the structures on low-dose images. Identification of anterior ethmoid artery (AEA) with reduced dose was insignificantly worse than with standard-dose examination. The AEA was scored as an average-defined structure and was the second weakest visualised. In conclusion, preoperatively, low-dose protocols may not sufficiently visualise the surgically relevant anatomical structures in patients with CRS and bronchial asthma, advanced nasal polyps (LS > 2) and history of sinus surgery. Low mAs value enables comparable detectability of sinonasal landmarks with standard-dose protocols in patients without analysed risk factors. In the context of planned surgery, the current preferences of the tube should be carefully evaluated for different patient constitutions to minimise the risk of complications.
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Abstract
While most patients with inflammatory rhinosinusitis are successfully diagnosed clinically, imaging is indicated in patients with recurrent or chronic sinusitis, atypical symptoms and complicated acute sinusitis. Non-enhanced high resolution, thin section computed tomography (CT) is the reference standard in evaluating such patients. It provides superb anatomical details and enables a fairly accurate diagnosis and delineation of the disease, addressing all concerns of the endoscopic surgeon prior to intervention. Contrast MR imaging is preferred for assessing intraorbital or intracranial complications. The radiologist must have a systematic approach to sinonasal CT and generate a clinically relevant report that impacts patient management.
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Affiliation(s)
- Varsha M Joshi
- Department of CT and MRI, Vijaya Diagnostics, Hyderabad, Telangana 500034, India; Visiting Consultant, Department of Imaging Tata Medical Center, Kolkata, India.
| | - Rima Sansi
- Department of CT and MRI, Vijaya Diagnostics, Hyderabad, Telangana 500034, India
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Bassim MK, Ebert CS, Sit RC, Senior BA. Radiation Dose to the Eyes and Parotids during CT of the Sinuses. Otolaryngol Head Neck Surg 2016; 133:531-3. [PMID: 16213924 DOI: 10.1016/j.otohns.2005.06.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2004] [Indexed: 11/19/2022]
Abstract
OBJECTIVE: To measure the radiation dose to the lens and parotid during high-resolution computed tomography scan of the sinuses. STUDY DESIGN AND SETTING: Nine cadaver heads were scanned in the axial plane by means of a fine-cut (0.75 mm) protocol. Images were then reconstructed in the coronal and sagittal planes for use with the image guidance software. Thermoluminescent dosimeters were taped over the eyes and parotids and used to measure the radiation dose absorbed by these organs. RESULTS: Doses obtained were 29.5 mGy for the lens and around 30 mGy for the parotid. CONCLUSION: The measured doses are lower than the reported acute thresholds of 500-2000 mGy for lens opacities and well below the threshold of 2500 mGy for damage to the parotid. SIGNIFICANCE: These results demonstrate minimal risk from radiation through the use of high-resolution computed tomography and support the use of such a protocol for diagnosis and preoperative planning.
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Affiliation(s)
- Marc K Bassim
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, NC 27599, USA.
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20
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Ferris H, Twomey M, Moloney F, O’Neill SB, Murphy K, O’Connor OJ, Maher M. Computed tomography dose optimisation in cystic fibrosis: A review. World J Radiol 2016; 8:331-341. [PMID: 27158420 PMCID: PMC4840191 DOI: 10.4329/wjr.v8.i4.331] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 10/15/2015] [Accepted: 01/19/2016] [Indexed: 02/06/2023] Open
Abstract
Cystic fibrosis (CF) is the most common autosomal recessive disease of the Caucasian population worldwide, with respiratory disease remaining the most relevant source of morbidity and mortality. Computed tomography (CT) is frequently used for monitoring disease complications and progression. Over the last fifteen years there has been a six-fold increase in the use of CT, which has lead to a growing concern in relation to cumulative radiation exposure. The challenge to the medical profession is to identify dose reduction strategies that meet acceptable image quality, but fulfil the requirements of a diagnostic quality CT. Dose-optimisation, particularly in CT, is essential as it reduces the chances of patients receiving cumulative radiation doses in excess of 100 mSv, a dose deemed significant by the United Nations Scientific Committee on the Effects of Atomic Radiation. This review article explores the current trends in imaging in CF with particular emphasis on new developments in dose optimisation.
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21
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Langner S. Optimized imaging of the midface and orbits. GMS CURRENT TOPICS IN OTORHINOLARYNGOLOGY, HEAD AND NECK SURGERY 2016; 14:Doc05. [PMID: 26770279 PMCID: PMC4702054 DOI: 10.3205/cto000120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A variety of imaging techniques are available for imaging the midface and orbits. This review article describes the different imaging techniques based on the recent literature and discusses their impact on clinical routine imaging. Imaging protocols are presented for different diseases and the different imaging modalities.
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Affiliation(s)
- Sönke Langner
- Institute for Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Germany
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22
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Hoxworth JM, Lal D. Universal sinus computed tomography protocol for diagnostic imaging and intraoperative navigation. ALLERGY & RHINOLOGY 2015; 6:146-50. [PMID: 26686204 PMCID: PMC5391481 DOI: 10.2500/ar.2015.6.0134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Background: Sinus computed tomography (CT) is performed for the diagnosis of paranasal sinus disease and to assess response to medical therapy. In addition, sinus CT is used for intraoperative imaging guidance. Multiple CTs increase cost and radiation exposure. Objective: To determine potential cost savings and radiation dose reduction that result from the use of a single universal sinus CT protocol for diagnostic imaging and intraoperative navigation. Materials and Methods: For sinus CT at the authors' institution, a single imaging protocol was begun and deemed acceptable by neuroradiologists and surgeons for diagnostic imaging and intraoperative guidance. The electronic medical record was queried over a 4-year period to determine the number of sinus CTs performed, dose-length products, referring providers' specialties, percentage of CTs used for intraoperative navigation, and the elapsed time between CT and surgery. Results: A total of 6187 sinus CTs were performed by using a 64-detector scanner during the study period (2759 women and 3428 men; 53.6 ± 16.7 years [mean ± SD]), and 596 endoscopic sinus surgery cases used imaging guidance, for which all the CTs were deemed technically adequate. The mean dose-length product for the CTs was 338.4 ± 31.9 mGy-cm (mean ± SD). Of the 3702 sinus CTs ordered by nonotolaryngology providers, 167 surgeries with intraoperative navigation (4.5%) were performed. A higher percentage of CT referrals from sinus surgeons (23.9%) and other otolaryngology providers (11.4%) was used for imaging guidance (p < 0.0001). The time interval between sinus CT and surgery was greatest for nonotolaryngology providers (63.1 days, p < 0.01). Based on Medicare reimbursement, the total estimated saving was $147,628. Conclusions: Adopting a single universal sinus CT protocol for diagnostic imaging and intraoperative navigation can be an effective means of decreasing cost and radiation exposure. However, successful implementation must take into account multiple practice-based considerations.
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Aksoy EA, Özden SU, Karaarslan E, Ünal ÖF, Tanyeri H. Reliability of high-pitch ultra-low-dose paranasal sinus computed tomography for evaluating paranasal sinus anatomy and sinus disease. J Craniofac Surg 2015; 25:1801-4. [PMID: 25203576 DOI: 10.1097/scs.0000000000000966] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES The aim of this study was to evaluate the reliability of high-pitch ultra-low-dose computed tomography (CT) for detecting important paranasal sinus anatomic landmarks and pathologies. MATERIALS AND METHODS Sixty patients (22 females, 38 males) aged 15 to 67 years (mean age, 33.68 y; SD, 9.83 y) underwent high-pitch ultra-low-dose CT of the paranasal sinuses between February and June 2012. To determine the lowest possible dose for evaluation of the paranasal sinuses, the patients were divided into three groups randomly and prospectively. A different low-dose CT protocol was applied to each group. The image quality was assessed subjectively by a radiologist and an otorhinolaryngology head and neck surgeon independently using a 4-point grading scale (0 = structures could not be identified, 1 = indistinctly defined structures, 1.5 = relatively well-defined structures, 2 = very well-defined structures). Anatomic landmarks and mucosal structures were evaluated. Mean scores were evaluated to assess statistical significance. RESULTS According to the anatomic landmark scoring, excluding the ethmoid foramen for ethmoid artery identification, all of the structures in all 3 groups were very well-defined structures. The ethmoid foramen for ethmoid artery identification was scored as either could not be identified or an indistinctly defined structure in all groups. On evaluating the mucosa of the paranasal sinuses, normal and pathologic mucosal structures were scored as very well defined in all of the patients. The interobserver agreement was excellent. CONCLUSION High-pitch ultra-low-dose CT is a safe, reliable paranasal sinus screening tool.
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Affiliation(s)
- Elif Ayanoglu Aksoy
- From the Departments of *Otorhinolaryngology and †Radiology, Faculty of Medicine, Acibadem University, Istanbul, Turkey
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Uzun I, Gunduz K, Celenk P, Avsever H, Orhan K, Canitezer G, Ozmen B, Cicek E, Egrioglu E. Comparing the Effect of Different Voxel Resolutions for Assessment of Vertical Root Fracture of Permanent Teeth. IRANIAN JOURNAL OF RADIOLOGY : A QUARTERLY JOURNAL PUBLISHED BY THE IRANIAN RADIOLOGICAL SOCIETY 2015; 12:e18290. [PMID: 26557279 PMCID: PMC4632561 DOI: 10.5812/iranjradiol.18290] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 10/22/2014] [Accepted: 12/01/2014] [Indexed: 11/16/2022]
Abstract
BACKGROUND The teeth with undiagnosed vertical root fractures (VRFs) are likely to receive endodontic treatment or retreatment, leading to frustration and inappropriate endodontic therapies. Moreover, many cases of VRFs cannot be diagnosed definitively until the extraction of tooth. OBJECTIVES This study aimed to assess the use of different voxel resolutions of two different cone beam computerized tomography (CBCT) units in the detection VRFs in vitro. MATERIALS AND METHODS The study material comprised 74 extracted human mandibular single rooted premolar teeth without root fractures that had not undergone any root-canal treatment. Images were obtained by two different CBCT units. Four image sets were obtained as follows: 1) 3D Accuitomo 170, 4 × 4 cm field of view (FOV) (0.080 mm(3)); 2) 3D Accuitomo 170. 6 × 6 cm FOV (0.125 mm(3)); 3) NewTom 3G, 6˝ (0.16 mm(3)) and 4) NewTom 3G, 9˝ FOV (0.25 mm(3)). Kappa coefficients were calculated to assess both intra- and inter-observer agreements for each image set. RESULTS No significant differences were found among observers or voxel sizes, with high average Z (Az) results being reported for all groups. Both intra- and inter-observer agreement values were relatively better for 3D Accuitomo 170 images than the images from NewTom 3G. The highest Az and kappa values were obtained with 3D Accuitomo 170, 4 × 4 cm FOV (0.080 mm(3)) images. CONCLUSION No significant differences were found among observers or voxel sizes, with high Az results reported for all groups.
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Affiliation(s)
- Ismail Uzun
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey
| | - Kaan Gunduz
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey
| | - Peruze Celenk
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey
| | - Hakan Avsever
- Department of Dentomaxillofacial Radiology, Gulhane Military Medical Academy (GATA), Ankara, Turkey
| | - Kaan Orhan
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Near East University, Mersin, Turkey
| | - Gozde Canitezer
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey
| | - Bilal Ozmen
- Department of Pedodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey
| | - Ersan Cicek
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey
| | - Erol Egrioglu
- Department of Statistics, Ondokuz Mayis University, Samsun, Turkey
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Manssor E, Abuderman A, Osman S, Alenezi SB, Almehemeid S, Babikir E, Alkhorayef M, Sulieman A. Radiation doses in chest, abdomen and pelvis CT procedures. RADIATION PROTECTION DOSIMETRY 2015; 165:194-198. [PMID: 25852181 DOI: 10.1093/rpd/ncv107] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Computed tomography (CT) scanning is recognised as a high-radiation dose modality and estimated to be 17 % of the radiological procedure and responsible for 70 % of medical radiation exposure. Although diagnostic X rays provide great benefits, their use involves some risk for developing cancer. The objectives of this study are to estimate radiation doses during chest, abdomen and pelvis CT. A total of 51 patients were examined for the evaluation of metastasis of a diagnosed primary tumour during 4 months. A calibrated CT machine from Siemens 64 slice was used. The mean age was 48.0 ± 18.6 y. The mean patient weight was 73.8 ± 16.1 kg. The mean dose-length product was 1493.8 ± 392.1 mGy cm, Volume CT dose index (CTDI vol) was 22.94 ± 5.64 mGy and the mean effective dose was 22.4 ± 5.9 mSv per procedure. The radiation dose per procedure was higher as compared with previous studies. Therefore, the optimisation of patient's radiation doses is required in order to reduce the radiation risk.
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Affiliation(s)
- E Manssor
- Radiology and Medical Imaging Department, Prince Sattam bin Abdulaziz University, College of Applied Medical Sciences, Alkharj, Saudi Arabia
| | - A Abuderman
- Basic Sciences Department, Sattam bin Abdulaziz University, College of Medicine, Alkharj, Saudi Arabia
| | - S Osman
- Radiology and Medical Imaging Department, Prince Sattam bin Abdulaziz University, College of Applied Medical Sciences, Alkharj, Saudi Arabia
| | - S B Alenezi
- Radiology Department, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - S Almehemeid
- Radiology Department, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - E Babikir
- Radiology Department, King Saud University, College of Applied Medical Science, Riyadh, Saudi Arabia
| | - M Alkhorayef
- Radiology Department, King Saud University, College of Applied Medical Science, Riyadh, Saudi Arabia
| | - A Sulieman
- Radiology and Medical Imaging Department, Prince Sattam bin Abdulaziz University, College of Applied Medical Sciences, Alkharj, Saudi Arabia
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Bodelle B, Wichmann JL, Klotz N, Lehnert T, Vogl TJ, Luboldt W, Schulz B. Seventy kilovolt ultra-low dose CT of the paranasal sinus: first clinical results. Clin Radiol 2015; 70:711-5. [PMID: 25912259 DOI: 10.1016/j.crad.2015.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 03/06/2015] [Accepted: 03/13/2015] [Indexed: 10/23/2022]
Abstract
AIM To evaluate the diagnostic image quality and radiation dose of low-dose 70 kV computed tomography (CT) of the paranasal sinus in comparison to 100 and 120 kV CT. MATERIALS AND METHODS CT of the paranasal sinus was performed in 127 patients divided into three groups using different tube voltages and currents (70 kV/75 mAs, ultra-low dose protocol, n = 44; 100 kV/40 mAs, standard low-dose protocol, n = 42; 120 kV/40 mAs, standard protocol, n = 41). CT dose index (CTDIvol), dose-length product (DLP), attenuation, image noise and signal-to-noise ratio (SNR) were compared between the groups using Wilcoxon-Mann-Whitney U-test. Subjective diagnostic image quality was compared by using a five-point scale (1 = non-diagnostic, 5 = excellent, read by two readers in consensus) and Cohen's weighted kappa analysis for interobserver agreement. RESULTS Radiation dose was significantly lower with 70 kV acquisition than 100 and 120 kV (DLP: 31 versus 52 versus 82 mGy·cm; CTDI 2.33 versus 3.95 versus 6.31 mGy, all p < 0.05). Mean SNR (70 kV: 0.37; 100 kV: 0.21; 120 kV: 0.13; p < 0.05) and organ attenuation increased significantly with lower voltages. All examinations showed diagnostic image quality. Subjective diagnostic image quality was higher with standard protocols than the 70 kV protocol (120 kV: 5.0; 100 kV: 4.5; 70 kV: 3.5, p < 0.05) without significant differences with substantial interobserver agreement (κ > 0.59). CONCLUSION The ultra-low dose (70 kV) CT imaging of the paranasal sinus allowed for significant dose reduction by 61% and an increased attenuation of organ structures in comparison to standard acquisition while maintaining diagnostic image quality with a slight reduction in subjective image quality.
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Affiliation(s)
- B Bodelle
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
| | - J L Wichmann
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - N Klotz
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - T Lehnert
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - T J Vogl
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - W Luboldt
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - B Schulz
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
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Celikten B, Uzuntas CF, Kursun S, Orhan AI, Tufenkci P, Orhan K, Demiralp KÖ. Comparative evaluation of shaping ability of two nickel-titanium rotary systems using cone beam computed tomography. BMC Oral Health 2015; 15:32. [PMID: 25887521 PMCID: PMC4358850 DOI: 10.1186/s12903-015-0019-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/20/2015] [Indexed: 12/02/2022] Open
Abstract
Background We evaluated and compared the effects of different NiTi rotary systems – ProTaper Next and New One Shape – on the volume of dentin removed, canal transportation, and canal curvature in extracted human teeth using CBCT scanning with different voxel sizes. Methods Fifty extracted human maxillary first molars with mesiobuccal canal curvature (25-35°) were used. Specimens were instrumented with the ProTaper Next or New One Shape. Pre- and post-instrumentation scans were performed to compare transportation at the levels of 2, 5, and 8 mm and volumes with two different voxel sizes (0.125-and 0.100-mm3) using 3D CBCT images. This study evaluated and compare the volume of dentin removed, canal transportation, and canal curvature. Differences according to instrumentation and voxel sizes were assessed using the Mann–Whitney U-test and the Wilcoxon signed-rank test. Results Significant differences were found between apical and coronal levels for both systems (p < 0.05) in canal transportation. In comparing the systems, similar values were found at each level, without significant difference (p > 0.05) in terms of canal curvature and volume. Voxel sizes did not affect the measurements on canal volume, curvature or transportation; no significant difference was found between the 0.100- and 0.125-mm3 voxel sizes (p > 0.05). Conclusions Both instrumentation systems produced similar canal transportation and volume changes. The two voxel resolutions also showed similar results, however a 0.125-mm3 voxel size can be recommend for a flat panel CBCT scanner with lower exposure dose.
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Affiliation(s)
- Berkan Celikten
- Faculty of Dentistry, Department of Endodontics, Ankara University, Besevler, 06560, Ankara, Turkey.
| | - Ceren Feriha Uzuntas
- Faculty of Dentistry, Department of Endodontics, Ankara University, Besevler, 06560, Ankara, Turkey.
| | - Sebnem Kursun
- Faculty of Dentistry, Department of DentoMaxillofacial Radiology, Ankara University, Besevler, 06560, Ankara, Turkey.
| | - Ayse Isil Orhan
- Division of Pediatric Dentistry, Ministry of Health, 75th Year Ankara Oral and Dental Health Centre, Cebeci, 06590, Ankara, Turkey.
| | - Pelin Tufenkci
- Faculty of Dentistry, Department of Endodontics, Ankara University, Besevler, 06560, Ankara, Turkey.
| | - Kaan Orhan
- Faculty of Dentistry, Department of DentoMaxillofacial Radiology, Ankara University, Besevler, 06560, Ankara, Turkey.
| | - Kemal Özgür Demiralp
- Ministry of Health, Public Hospitals Agency of Turkey, Bahcelievler, 06490, Ankara, Turkey.
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Zou J, Koivisto J, Lähelmä J, Aarnisalo A, Wolff J, Pyykkö I. Imaging Optimization of Temporal Bones With Cochlear Implant Using a High-resolution Cone Beam CT and the Corresponding Effective Dose. Ann Otol Rhinol Laryngol 2014; 124:466-73. [DOI: 10.1177/0003489414565004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective: To evaluate the impact of tube voltage, tube current, pulse number, and magnification factor on the image quality of a novel experimental set-up and the corresponding radiation. Materials and Methods: Six human temporal bones with cochlear implant were imaged using various tube voltages, tube currents, pulse numbers, and magnification. The effect of radiation was evaluated using a metaloxide semiconductor field-effect transistor (MOSFET) dosimeter device on an anthropomorphic RANDO RAN102 male head phantom. A copper and aluminum combination filter was used for hardware filtration. Results: Overall, 900 frames, 11 mA, and 88 kV provided the best image quality. In temporal bones imaged with the optimized parameters, the cochlea, osseous spiral lamina, modiolus, stapes, round window niche, and oval window landmarks were demonstrated with anatomic structures still fully assessable in all parts and acceptable image quality. The most dominant contributor to the effective dose was bone marrow (36%-37 %) followed by brain (34%-36%), remainder tissues (12%), extra-thoracic airways (7%), and oral mucosa (5%). Conclusions: By increasing the number of frames, the image quality of the inner ear details obtained using the novel cone-beam computed tomography improved.
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Affiliation(s)
- Jing Zou
- Hearing and Balance Research Unit, Field of Otolaryngology, School of Medicine, University of Tampere, Tampere, Finland
- Department of Otolaryngology-Head and Neck Surgery, Center for Otolaryngology-Head & Neck Surgery of Chinese PLA, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Juha Koivisto
- Department of Physics, University of Helsinki, Helsinki, Finland
| | | | - Antti Aarnisalo
- Department of Otorhinolaryngology-Head and Neck Surgery, Helsinki University Central Hospital, Helsinki, Finland
| | - Jan Wolff
- Hearing and Balance Research Unit, Field of Otolaryngology, School of Medicine, University of Tampere, Tampere, Finland
- Department of Oral and Maxillofacial Surgery/Oral Pathology, VU University Medical Center, Amsterdam, the Netherlands
| | - Ilmari Pyykkö
- Hearing and Balance Research Unit, Field of Otolaryngology, School of Medicine, University of Tampere, Tampere, Finland
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Leiva-Salinas C, Flors L, Gras P, Más-Estellés F, Lemercier P, Patrie JT, Wintermark M, Martí-Bonmatí L. Dental flat panel conebeam CT in the evaluation of patients with inflammatory sinonasal disease: Diagnostic efficacy and radiation dose savings. AJNR Am J Neuroradiol 2014; 35:2052-7. [PMID: 24970545 DOI: 10.3174/ajnr.a4019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE CT is the imaging modality of choice to study the paranasal sinuses; unfortunately, it involves significant radiation dose. Our aim was to assess the diagnostic validity, image quality, and radiation-dose savings of dental conebeam CT in the evaluation of patients with suspected inflammatory disorders of the paranasal sinuses. MATERIAL AND METHODS We prospectively studied 40 patients with suspected inflammatory disorders of the sinuses with dental conebeam CT and standard CT. Two radiologists analyzed the images independently, blinded to clinical information. The image quality of both techniques and the diagnostic validity of dental conebeam CT compared with the reference standard CT were assessed by using 3 different scoring systems. Image noise, signal-to-noise ratio, and contrast-to-noise ratio were calculated for both techniques. The absorbed radiation dose to the lenses and thyroid and parotid glands was measured by using a phantom and dosimeter chips. The effective radiation dose for CT was calculated. RESULTS All dental conebeam CT scans were judged of diagnostic quality. Compared with CT, the conebeam CT image noise was 37.3% higher (P < .001) and the SNR of the bone was 75% lower (P < .001). The effective dose of our conebeam CT protocol was 23 μSv. Compared with CT, the absorbed radiation dose to the lenses and parotid and thyroid glands with conebeam CT was 4%, 7.8%, and 7.3% of the dose delivered to the same organs by conventional CT (P < .001). CONCLUSIONS Dental conebeam CT is a valid imaging procedure for the evaluation of patients with inflammatory sinonasal disorders.
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Affiliation(s)
- C Leiva-Salinas
- From the Departments of Radiology and Medical Imaging (C.L.-S., L.F., F.M.-E., P.L., L.M.-B.) Departments of Radiology and Medical Imaging (C.L.-S., L.F., M.W.)
| | - L Flors
- From the Departments of Radiology and Medical Imaging (C.L.-S., L.F., F.M.-E., P.L., L.M.-B.) Departments of Radiology and Medical Imaging (C.L.-S., L.F., M.W.)
| | | | - F Más-Estellés
- From the Departments of Radiology and Medical Imaging (C.L.-S., L.F., F.M.-E., P.L., L.M.-B.) ERESA (F.M.-E.)
| | - P Lemercier
- From the Departments of Radiology and Medical Imaging (C.L.-S., L.F., F.M.-E., P.L., L.M.-B.)
| | - J T Patrie
- Public Health Sciences (J.T.P.), University of Virginia, Charlottesville, Virginia
| | - M Wintermark
- Departments of Radiology and Medical Imaging (C.L.-S., L.F., M.W.)
| | - L Martí-Bonmatí
- From the Departments of Radiology and Medical Imaging (C.L.-S., L.F., F.M.-E., P.L., L.M.-B.) GIBI Research Group (L.M.-B.), Hospital Universitario y Politécnico la Fe, Valencia, Spain
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Hoxworth JM, Lal D, Fletcher GP, Patel AC, He M, Paden RG, Hara AK. Radiation dose reduction in paranasal sinus CT using model-based iterative reconstruction. AJNR Am J Neuroradiol 2014; 35:644-9. [PMID: 24113467 DOI: 10.3174/ajnr.a3749] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE CT performed with Veo model-based iterative reconstruction has shown the potential for radiation-dose reduction. This study sought to determine whether Veo could reduce noise and improve the image quality of low-dose sinus CT. MATERIALS AND METHODS Twenty patients consented to participate and underwent low- and standard-dose sinus CT on the same day. Standard-dose CT was created with filtered back-projection (120 kV[peak], 210 mA, 0.4-second rotation, and 0.531 pitch). For low-dose CT, mA was decreased to 20 (the remaining parameters were unchanged), and images were generated with filtered back-projection and Veo. Standard- and low-dose datasets were reconstructed by using bone and soft-tissue algorithms, while the low-dose Veo reconstruction only had a standard kernel. Two blinded neuroradiologists independently evaluated the image quality of multiple osseous and soft-tissue craniofacial structures. Image noise was measured by using multiple regions of interest. RESULTS Eight women and 12 men (mean age, 63.3 years) participated. Volume CT dose indices were 2.9 mGy (low dose) and 31.6 mGy (standard dose), and mean dose-length products were 37.4 mGy-cm (low dose) and 406.1 mGy-cm (standard dose). Of all the imaging series, low-dose Veo demonstrated the least noise (P < .001). Compared with filtered back-projection low-dose CT using soft-tissue and bone algorithms, Veo had the best soft-tissue image quality but the poorest bone image quality (P < .001). CONCLUSIONS Veo significantly reduces noise in low-dose sinus CT. Although this reduction improves soft-tissue evaluation, thin bone becomes less distinct.
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Affiliation(s)
- J M Hoxworth
- From the Departments of Radiology (J.M.H., G.P.F., A.C.P., R.G.P, A.K.H.)
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Xia W, Wu JT, Yin XR, Wang ZJ, Wu HT. CT angiography of the neck: Value of contrast medium dose reduction with low tube voltage and high tube current in a 64–detector row CT. Clin Radiol 2014; 69:e183-9. [PMID: 24503560 DOI: 10.1016/j.crad.2013.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 11/09/2013] [Accepted: 12/02/2013] [Indexed: 11/18/2022]
Affiliation(s)
- W Xia
- Clinical Medical College, Yangzhou University, Radiology Department, Subei People's Hospital of Jiangsu Province, Yangzhou, China
| | - J-T Wu
- Clinical Medical College, Yangzhou University, Radiology Department, Subei People's Hospital of Jiangsu Province, Yangzhou, China.
| | - X-R Yin
- Radiology Department, Huashan Hospital, Fudan University, Shanghai, China
| | - Z-J Wang
- Clinical Medical College, Yangzhou University, Radiology Department, Subei People's Hospital of Jiangsu Province, Yangzhou, China
| | - H-T Wu
- Clinical Medical College, Yangzhou University, Radiology Department, Subei People's Hospital of Jiangsu Province, Yangzhou, China
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Hong SS, Lee JW, Seo JB, Jung JE, Choi J, Kweon DC. Evaluation of image quality and radiation dose by adaptive statistical iterative reconstruction technique level for chest CT examination. RADIATION PROTECTION DOSIMETRY 2013; 157:163-171. [PMID: 23704358 DOI: 10.1093/rpd/nct127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The purpose of this research is to determine the adaptive statistical iterative reconstruction (ASIR) level that enables optimal image quality and dose reduction in the chest computed tomography (CT) protocol with ASIR. A chest phantom with 0-50 % ASIR levels was scanned and then noise power spectrum (NPS), signal and noise and the degree of distortion of peak signal-to-noise ratio (PSNR) and the root-mean-square error (RMSE) were measured. In addition, the objectivity of the experiment was measured using the American College of Radiology (ACR) phantom. Moreover, on a qualitative basis, five lesions' resolution, latitude and distortion degree of chest phantom and their compiled statistics were evaluated. The NPS value decreased as the frequency increased. The lowest noise and deviation were at the 20 % ASIR level, mean 126.15 ± 22.21. As a result of the degree of distortion, signal-to-noise ratio and PSNR at 20 % ASIR level were at the highest value as 31.0 and 41.52. However, maximum absolute error and RMSE showed the lowest deviation value as 11.2 and 16. In the ACR phantom study, all ASIR levels were within acceptable allowance of guidelines. The 20 % ASIR level performed best in qualitative evaluation at five lesions of chest phantom as resolution score 4.3, latitude 3.47 and the degree of distortion 4.25. The 20 % ASIR level was proved to be the best in all experiments, noise, distortion evaluation using ImageJ and qualitative evaluation of five lesions of a chest phantom. Therefore, optimal images as well as reduce radiation dose would be acquired when 20 % ASIR level in thoracic CT is applied.
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Affiliation(s)
- Sun Suk Hong
- Department of Radiology, Asan Medical Center, Seoul 138-736, Korea
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Neves FS, Souza TDC, de-Azevedo-Vaz SL, Campos PSF, Bóscolo FN. Influence of cone-beam computed tomography milliamperage settings on image quality of the mandibular third molar region. Oral Radiol 2013. [DOI: 10.1007/s11282-013-0132-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Esophageal squamous cell carcinoma: assessing tumor angiogenesis using multi-slice CT perfusion imaging. Dig Dis Sci 2012; 80:284-91. [PMID: 22476585 DOI: 10.1016/j.ejrad.2010.07.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 07/07/2010] [Indexed: 12/12/2022]
Abstract
OBJECTIVES The purpose of this study was to investigate the correlation between multi-slice computed tomographic perfusion imaging (CTPI) parameters and immunohistologic markers of angiogenesis in esophageal squamous cell carcinoma (ESCC). METHODS Fifty patients with histologically proven esophageal squamous cell carcinoma were enrolled in this study. All subjects underwent multi-slice CT perfusion scan. The hemodynamic parameters of vascular tumor, including blood volume (BV), blood flow (BF), mean transit time (MTT) and permeability surface (PS) were generated. All the ESCC specimens were stained immunohistochemically to identify CD31 for quantification of microvessel density (MVD). CTPI parameters were correlated with MVD by using Pearson correlation analysis. RESULTS The value of CT perfusion parameters of ESCC were as follows: BF 116.71 ± 47.59 ml/100 g/min, BV 6.74 ± 2.70 ml/100 g, MTT 6.42 ± 2.84 s, PS 13.82 ± 6.25 ml/100 g/min. The mean MVD of all 50 tumor specimens was 34.44 ± 19.75. The PS values were significantly higher in ESCC patients with involvement of lymph node than those without involvement of lymph node (p < 0.01). Blood volume and permeability surface were positively correlated with MVD (p < 0.01), whereas no significant correlation was observed between MVD and BF or between MVD and MTT. CONCLUSIONS Blood volume and permeability surface were positively correlated with MVD. CTPI could reflect the angiogenesis in ESCC.
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Wang JW, Tang C, Pan BR. Data analysis of low dose multislice helical CT scan in orbital trauma. Int J Ophthalmol 2012; 5:366-9. [PMID: 22773989 DOI: 10.3980/j.issn.2222-3959.2012.03.22] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 05/26/2012] [Indexed: 11/02/2022] Open
Abstract
AIM To explore the optimal low dose of MSCT in orbital trauma examination. METHODS Sixty transverse images of the fracture layer were selected. Low-dose images acquired at 30, 70, 100, 140, 170, and 200 milliampere (mA) were simulated by adding noise to the image space using software. After assessing the images according to the conditions of image quality and fracture, we found the optimal tube current that met diagnostic requirements and then applied it to clinical use. The CT Dose Index volume (CTDIvol), dose length product (DLP) and effective dose (ED) were recorded. The image quality was classified as good, fairly good, ordinary, poor, or very poor according to image level, noise, anatomic structure and whether the diagnostic requirements were met or not. The rank-sum test was used to perform statistical analysis on the ranked data. The Chi-square test was used for the numerical data. RESULTS Under the scan conditions of a conventional dose of 300 mA, 60 cases of orbital fracture, 38 cases of orbital emphysema, 25 cases of ocular damage, and 3 cases of intraorbital foreign body were demonstrated in the images of the 60 orbital trauma patients. Among the low dose simulated images, the image quality difference of the different doses was of statistical significance (χ(2)=15.678, P=0.016). When the dose was lowered to 70 mA, the above mentioned clinical signs were still clear and diagnostic, however the image quality assessment results indicated that 2 cases were good, 16 cases were fairly good, and 42 cases were ordinary, poor or very poor. When the simulated dose tube current was 100mA, the image quality assessment results were 18 cases good, 34 cases fairly good, and 8 cases ordinary, poor and very poor; compared with the conventional dose, there was no statistical significance (P>0.05). When using a 100 mA tube current to examine 40 cases of orbital trauma patients in the clinic, the acquired image quality was 10 cases good, 26 cases fairly good and 4 cases ordinary, without any cases of poor or very poor. The CTDIvol, DLP and ED were 20.72mGy, 124.97 mGy·cm and 0.26mSv, respectively, while the CTDIvol, DLP and ED were 62.53mGy, 375.18 mGy•GTtl and 0.86mSv, respectively, when using a conventional dose of 300 mA. Compared with the tube current of 100 mA for scanning, the ED declined 70%. CONCLUSION When conducting an MSCT scan for orbital trauma, the acquired images using the 100 mA tube current can meet the clinical diagnostic requirements, and the radiation dose to the patients can be decreased.
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Affiliation(s)
- Ji-Wei Wang
- Department of Radiology, People's Hospital of Zhengzhou, Zhengzhou 450003, Henan Province, China
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Aprile I, Ottaviano I, Buono E, Di Renzo A, Fiaschini P, Ottaviano P. Low-dose brain computer tomography sensitivity: a comparative study with a conventional technique. Neuroradiol J 2012; 25:151-62. [PMID: 24028908 DOI: 10.1177/197140091202500201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 03/13/2012] [Indexed: 11/15/2022] Open
Abstract
A comparative study between brain conventional computed tomography (CT) examinations and low-dose examinations was performed. The aim of the work was to show if a low-dose technique can be used instead of a standard one. Forty patients with 51 brain lesions were studied with both techniques. The low-dose technique was optimized with mAs reduction to obtain a 25% dose reduction compared to standard acquisitions. Even if images have a poor signal-to-noise ratio, the low-dose technique visualized all the lesions disclosed by conventional examination except three chronic vascular lacunar infarcts. In conclusion, the low-dose technique can be adopted instead conventional CT scans in selected cases.
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Affiliation(s)
- I Aprile
- Neuroradiology Unit, Department of Imaging Diagnostics, S. Maria Hospital; Terni, Italy -
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Effect of low tube voltage on image quality, radiation dose, and low-contrast detectability at abdominal multidetector CT: phantom study. J Biomed Biotechnol 2012; 2012:130169. [PMID: 22619490 PMCID: PMC3347747 DOI: 10.1155/2012/130169] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 02/19/2012] [Accepted: 02/24/2012] [Indexed: 01/11/2023] Open
Abstract
PURPOSE To investigate the effect of low tube voltage (80 kV) on image quality, radiation dose, and low-contrast detectability (LCD) at abdominal computed tomography (CT). MATERIALS AND METHODS A phantom containing low-contrast objects was scanned with a CT scanner at 80 and 120 kV, with tube current-time product settings at 150-650 mAs. The differences between image noise, contrast-to-noise ratio (CNR), and scores of LCD obtained with 80 kV at 150-650 mAs and those obtained with 120 kV at 300 mAs were compared respectively. RESULTS The image noise substantially increased with low tube voltage. However, with identical dose, use of 80 kV resulted in higher CNR compared with CNR at 120 kV. There were no statistically significant difference in CNR and scores of LCD between 120 kV at 300 mAs and 80 kV at 550-650 mAs (P > 0.05). The relative dose delivered at 80 kV ranged from 58% at 550 mAs to 68% at 650 mAs. CONCLUSION With a reduction of the tube voltage from 120 kV to 80 kV at abdominal CT, the radiation dose can be reduced by 32% to 42% without degradation of CNR and LCD.
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Bulla S, Blanke P, Hassepass F, Krauss T, Winterer JT, Breunig C, Langer M, Pache G. Reducing the radiation dose for low-dose CT of the paranasal sinuses using iterative reconstruction: feasibility and image quality. Eur J Radiol 2011; 81:2246-50. [PMID: 21664084 DOI: 10.1016/j.ejrad.2011.05.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 04/20/2011] [Accepted: 05/09/2011] [Indexed: 10/18/2022]
Abstract
PURPOSE To evaluate image quality of dose-reduced CT of the paranasal-sinus using an iterative reconstruction technique. METHODS In this study 80 patients (mean age: 46.9±18 years) underwent CT of the paranasalsinus (Siemens Definition, Forchheim, Germany), with either standard settings (A: 120 kV, 60 mAs) reconstructed with conventional filtered back projection (FBP) or with tube current-time product lowering of 20%, 40% and 60% (B: 48 mAs, C: 36 mAs and D: 24 mAs) using iterative reconstruction (n=20 each). Subjective image quality was independently assessed by four blinded observers using a semiquantitative five-point grading scale (1=poor, 5=excellent). Effective dose was calculated from the dose-length product. Mann-Whitney-U-test was used for statistical analysis. RESULTS Mean effective dose was 0.28±0.03 mSv(A), 0.23±0.02 mSv(B), 0.17±0.02 mSv(C) and 0.11±0.01 mSv(D) resulting in a maximum dose reduction of 60% with iterative reconstruction technique as compared to the standard low-dose CT. Best image quality was observed at 48 mAs (mean 4.8; p<0.05), whereas standard low-dose CT (A) and maximum dose reduced scans (D) showed no significant difference in subjective image quality (mean 4.37 (A) and 4.31 (B); p=0.72). Interobserver agreement was excellent (κ values 0.79-0.93). CONCLUSION As compared to filtered back projection, the iterative reconstruction technique allows for significant dose reduction of up to 60% for paranasal-sinus CT without impairing the diagnostic image quality.
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Affiliation(s)
- Stefan Bulla
- Department of Diagnostic Radiology, University Hospital Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany.
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Recommandations pour la surveillance médicoprofessionnelle des travailleurs exposés à l’effet cancérigène des poussières de bois. ARCH MAL PROF ENVIRO 2011. [DOI: 10.1016/j.admp.2011.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Impact of Adaptive Statistical Iterative Reconstruction (ASIR) on Radiation Dose and Image Quality in Aortic Dissection Studies: A Qualitative and Quantitative Analysis. AJR Am J Roentgenol 2011; 196:W336-40. [DOI: 10.2214/ajr.10.4573] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abul-Kasim K, Strömbeck A, Sahlstrand-Johnson P. Low-dose computed tomography of the paranasal sinuses: radiation doses and reliability analysis. Am J Otolaryngol 2011; 32:47-51. [PMID: 20015806 DOI: 10.1016/j.amjoto.2009.08.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2009] [Revised: 08/28/2009] [Accepted: 08/30/2009] [Indexed: 10/24/2022]
Abstract
PURPOSE The study aimed to (1) optimize the radiation doses of computed tomography (CT) of paranasal sinuses, (2) compare the radiation doses of different CT protocols with that of plain radiography, and (3) evaluate the reliability of low-dose CT in the detection of pathology and characterization of the detected pathology. MATERIALS AND METHODS A head phantom was examined with different scan parameters to define a cutoff value to which the radiation dose can be reduced without negative impact on image quality. Kruskal-Wallis test and Wilcoxon W test were performed to compare the effective doses of the plain radiography in 30 patients with that of 3 different CT protocols in a total of 90 patients. The interobserver and intraobserver agreement in the detection of pathologic findings and in characterization of the pathology was estimated by calculating κ value. RESULTS The effective doses of plain radiography and low-dose CT were 0.098 and 0.045 mSv, respectively (P < .001). The effective dose of standard CT of sinuses (0.371 mSv) was 3.8 times higher than that of plain radiography and 8.2 times higher than that of low-dose CT (P < .001). The interobserver and intraobserver agreement on CT with regard to detection of pathology and pathology characterization was almost perfect (κ values 0.81-1) compared to fair (κ values 0.38-0.39) in plain radiography. CONCLUSIONS The here proposed low-dose CT means significant dose reduction and is a reliable method in the investigation of the paranasal sinuses.
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Yiğit Özer S. Detection of Vertical Root Fractures by Using Cone Beam Computed Tomography with Variable Voxel Sizes in an In Vitro Model. J Endod 2011; 37:75-9. [DOI: 10.1016/j.joen.2010.04.021] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 04/02/2010] [Accepted: 04/29/2010] [Indexed: 10/18/2022]
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Iezzi R, Cotroneo AR, Giammarino A, Spigonardo F, Storto ML. Low-dose multidetector-row CT-angiography of abdominal aortic aneurysm after endovascular repair. Eur J Radiol 2009; 79:21-8. [PMID: 20007012 DOI: 10.1016/j.ejrad.2009.11.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 11/02/2009] [Accepted: 11/04/2009] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate the possibility of reducing radiation dose exposure while maintaining image quality using multidetector computed tomography angiography (MDCTA) with high-concentration contrast media in patients undergoing follow-up after endovascular aortic repair (EVAR) to treat abdominal aortic aneurysm. MATERIALS AND METHODS In this prospective, single center, intra-individual study, patients underwent two consecutive MDCTA scans 6 months apart, one with a standard acquisition protocol (130 mAs/120 kV) and 120 mL of iomeprol 300, and one using a low dose protocol (100 mAs/80 kV) and 90 mL of iomeprol 400. Images acquired during the arterial phase of contrast enhancement were evaluated both qualitatively and quantitatively for image noise and intraluminal contrast enhancement. RESULTS Thirty adult patients were prospectively enrolled. Statistically significantly higher attenuation values were measured in the low-dose acquisition protocol compared to the standard protocol, from the suprarenal abdominal aorta to the common femoral artery (p<0.0001; all vascular segments). Qualitatively, image quality was judged significantly (p=0.0002) better with the standard protocol than with the low-dose protocol. However, no significant differences were found between the two protocols in terms of contrast-to-noise ratio (CNR) (13.63±6.97 vs. 11.48±8.13; p=0.1058). An overall dose reduction of up to 74% was observed for the low-dose protocol compared with the standard protocol. CONCLUSION In repeat follow-up examinations of patients undergoing EVAR for abdominal aortic aneurysm, a low-dose radiation exposure acquisition protocol provides substantially reduced radiation exposure while maintaining a constant CNR and good image quality.
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Affiliation(s)
- R Iezzi
- Department of Bioimaging and Radiological Sciences, Institute of Radiology, "A. Gemelli" Hospital - Catholic University, L.go A Gemelli 8, 00168 Rome, Italy.
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Lee EJ, Lee SK, Agid R, Howard P, Bae JM, terBrugge K. Comparison of image quality and radiation dose between fixed tube current and combined automatic tube current modulation in craniocervical CT angiography. AJNR Am J Neuroradiol 2009; 30:1754-9. [PMID: 19509074 DOI: 10.3174/ajnr.a1675] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The combined automatic tube current modulation (ATCM) technique adapts and modulates the x-ray tube current in the x-y-z axis according to the patient's individual anatomy. We compared image quality and radiation dose of the combined ATCM technique with those of a fixed tube current (FTC) technique in craniocervical CT angiography performed with a 64-section multidetector row CT (MDCT) system. MATERIALS AND METHODS A retrospective review of craniocervical CT angiograms (CTAs) by using combined ATCM (n = 25) and FTC techniques (n = 25) was performed. Other CTA parameters, such as kilovolt (peak), matrix size, FOV, section thickness, pitch, contrast agent, and contrast injection techniques, were held constant. We recorded objective image noise in the muscles at 2 anatomic levels: radiation exposure doses (CT dose index volume and dose-length product); and subjective image quality parameters, such as vascular delineation of various arterial vessels, visibility of small arterial detail, image artifacts, and certainty of diagnosis. The Mann-Whitney U test was used for statistical analysis. RESULTS No significant difference was detected in subjective image quality parameters between the FTC and combined ATCM techniques. Most subjects in both study groups (49/50, 98%) had acceptable subjective artifacts. The objective image noise values at shoulder level did not show a significant difference, but the noise value at the upper neck was higher with the combined ATCM (P < .05) technique. Significant reduction in radiation dose (18% reduction) was noted with the combined ATCM technique (P < .05). CONCLUSIONS The combined ATCM technique for craniocervical CTA performed at 64-section MDCT substantially reduced radiation exposure dose but maintained diagnostic image quality.
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Affiliation(s)
- E J Lee
- Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada
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Lam SY, Bux SI, Kumar G, Ng KH, Hussain AF. A comparison between low-dose and standard-dose non-contrasted multidetector CT scanning of the paranasal sinuses. Biomed Imaging Interv J 2009; 5:e13. [PMID: 21611051 PMCID: PMC3097781 DOI: 10.2349/biij.5.3.e13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 06/10/2009] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To compare the image quality of the low-dose to the standard-dose protocol of MDCT scanning of the paranasal sinuses, based on subjective assessment and determine the radiation doses to the eyes and thyroid gland and dose reduction between these two protocols. MATERIALS AND METHODS 31 adult patients were scanned. Prior to scanning, thermoluminescent dosimeters (TLDs) were placed at 4 sites: outer canthus of right eye, outer canthus of left eye, inner canthus and anterior neck (thyroid gland). Every patient was scanned twice using the standard-dose protocol (100mAs) followed by the low-dose protocol (40mAs). The images were reviewed by 3 radiologists. Wilcoxon test was used as the test of significance for the image quality assessments. The paired sample t-test was used as the test of significance for the analysis of the radiation doses measured by the TLDs. RESULTS Of the 30 patients selected for analysis, this study showed no significant difference in the scores for the diagnostic image quality and the anatomical structures assessments between the two protocols. The average calculated mean entrance surface doses and standard deviation for the standard-dose and low-dose protocols were 12.40±1.39 mGy and 5.53±0.82 mGy respectively to the lens and 1.03±0.55 mGy and 0.63±0.53 mGy respectively to the thyroid gland. CONCLUSION The reduction of mAs from 100 to 40 resulted in a significant reduction of the radiation doses to the lens and thyroid gland by 55.4% and 38.8% respectively without causing any significant effect to the diagnostic image quality and assessment of the anatomical structures.
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Affiliation(s)
- SY Lam
- Department of Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia
| | - SI Bux
- Department of Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia
| | - G Kumar
- Department of Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia
| | - KH Ng
- Department of Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia
| | - AF Hussain
- Department of Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia
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Ramadan HH. Safety and feasibility of balloon sinuplasty for treatment of chronic rhinosinusitis in children. Ann Otol Rhinol Laryngol 2009; 118:161-5. [PMID: 19374145 DOI: 10.1177/000348940911800301] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES Balloon sinuplasty is a new technique that was recently introduced for the treatment of chronic rhinosinusitis (CRS). The initial experience in adults has been promising. The technique allows for restoring ventilation to the sinuses with minimal risk and trauma to the tissues. I present our initial experience of its use for treatment of CRS in children. METHODS I performed a prospective study of 30 children in whom medical therapy failed and who were scheduled for surgery. They were offered treatment with balloon sinuplasty of selected sinuses. The data collected included age, computed tomography score, and comorbid conditions. The primary outcome was the intraoperative success of dilation of the sinuses and the rate of adverse events due to the procedure. RESULTS The procedure was successful in 51 of 56 sinuses (91%) in 30 children. Five sinuses, of which 4 were hypoplastic maxillary sinuses and 1 was a frontal sinus, were not amenable to dilation. No complications or side effects were noted. CONCLUSIONS The initial experience with balloon sinuplasty in children seems to be very encouraging. Because there is no bone or tissue removal, the procedure seems to be suitable for use in children. A hypoplastic sinus may not be amenable to balloon sinuplasty.
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Affiliation(s)
- Hassan H Ramadan
- Department of Otolaryngology-Head and Neck Surgery, West Virginia University, Morgantown, West Virginia 26505, USA
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Nemec SF, Peloschek P, Koelblinger C, Mehrain S, Krestan CR, Czerny C. Sinonasal imaging after Caldwell–Luc surgery: MDCT findings of an abandoned procedure in times of functional endoscopic sinus surgery. Eur J Radiol 2009; 70:31-4. [DOI: 10.1016/j.ejrad.2008.01.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 12/19/2007] [Accepted: 01/10/2008] [Indexed: 10/22/2022]
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Nauer CB, Eichenberger A, Dubach P, Gralla J, Caversaccio M. CT radiation dose for computer-assisted endoscopic sinus surgery: dose survey and determination of dose-reduction limits. AJNR Am J Neuroradiol 2009; 30:617-22. [PMID: 19022868 DOI: 10.3174/ajnr.a1378] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Computer-assisted navigation is increasingly used in functional endoscopic sinus surgery (FESS) to prevent injury to vital structures, necessitating preparative CT and, thus, radiation exposure. The purpose of our study was to investigate currently used radiation doses for CT in computer-assisted navigation in sinus surgery (CAS-CT) and to assess minimal doses required. MATERIALS AND METHODS A questionnaire inquiring about dose parameters used for CAS-CT was sent to 30 radiologic institutions. The feasibility of low-dose registration was tested with a phantom. The influence of CAS-CT dose on technical accuracy and on the practical performance of 5 ear, nose, and throat (ENT) surgeons was evaluated with cadaver heads. RESULTS The questionnaire response rate was 63%. Variation between minimal and maximal dose used for CAS-CT was 18-fold. Phantom registration was possible with doses as low as 1.1 mGy. No dose dependence on technical accuracy was found. ENT surgeons were able to identify anatomic landmarks on scans with a dose as low as 3.1 mGy. CONCLUSIONS The vast dose difference between institutions mirrors different attitudes toward image quality and radiation-protection issues rather than being technically founded, and many patients undergo CAS-CT at higher doses than necessary. The only limit for dose reduction in CT for computer-assisted endoscopic sinus surgery is the ENT surgeon's ability to cope with impaired image quality, whereas there is no technically justified lower dose limit. We recommend, generally, doses used for the typical diagnostic low-dose sinus CT (120 kV/20-50 mAs). When no diagnostic image quality is needed, even a reduction down to a third is possible.
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Affiliation(s)
- C B Nauer
- Institute for Diagnostic and Interventional Neuroradiology, University Hospital and University of Berne, Berne, Switzerland.
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Olszewski R, Reychler H, Cosnard G, Denis JM, Vynckier S, Zech F. Accuracy of three-dimensional (3D) craniofacial cephalometric landmarks on a low-dose 3D computed tomograph. Dentomaxillofac Radiol 2008; 37:261-7. [DOI: 10.1259/dmfr/33343444] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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