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Ippolito D, Porta M, Maino C, Riva L, Ragusi M, Giandola T, Franco PN, Cangiotti C, Gandola D, De Vito A, Talei Franzesi C, Corso R. Feasibility of Low-Dose and Low-Contrast Media Volume Approach in Computed Tomography Cardiovascular Imaging Reconstructed with Model-Based Algorithm. Tomography 2024; 10:286-298. [PMID: 38393291 PMCID: PMC10891780 DOI: 10.3390/tomography10020023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/02/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024] Open
Abstract
Aim: To evaluate the dose reduction and image quality of low-dose, low-contrast media volume in computed tomography (CT) examinations reconstructed with the model-based iterative reconstruction (MBIR) algorithm in comparison with the hybrid iterative (HIR) one. Methods: We prospectively enrolled a total of 401 patients referred for cardiovascular CT, evaluated with a 256-MDCT scan with a low kVp (80 kVp) reconstructed with an MBIR (study group) or a standard HIR protocol (100 kVp-control group) after injection of a fixed dose of contrast medium volume. Vessel contrast enhancement and image noise were measured by placing the region of interest (ROI) in the left ventricle, ascending aorta; left, right and circumflex coronary arteries; main, right and left pulmonary arteries; aortic arch; and abdominal aorta. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were computed. Subjective image quality obtained by consensus was assessed by using a 4-point Likert scale. Radiation dose exposure was recorded. Results: HU values of the proximal tract of all coronary arteries; main, right and left pulmonary arteries; and of the aorta were significantly higher in the study group than in the control group (p < 0.05), while the noise was significantly lower (p < 0.05). SNR and CNR values in all anatomic districts were significantly higher in the study group (p < 0.05). MBIR subjective image quality was significantly higher than HIR in CCTA and CTPA protocols (p < 0.05). Radiation dose was significantly lower in the study group (p < 0.05). Conclusions: The MBIR algorithm combined with low-kVp can help reduce radiation dose exposure, reduce noise, and increase objective and subjective image quality.
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Affiliation(s)
- Davide Ippolito
- Departement of Medicine and Surgery, University of Milano-Bicocca, Piazza OMS 1, 20100 Milano, Italy;
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Marco Porta
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Cesare Maino
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Luca Riva
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Maria Ragusi
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Teresa Giandola
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Paolo Niccolò Franco
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Cecilia Cangiotti
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Davide Gandola
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Andrea De Vito
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Cammillo Talei Franzesi
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
| | - Rocco Corso
- Department of Diagnostic Radiology, Fondazione IRCCS Fondazione San Gerardo dei Tintori, Via Pergolesi 33, 20900 Monza, Italy; (M.P.); (L.R.); (M.R.); (T.G.); (P.N.F.); (C.C.); (D.G.); (A.D.V.); (C.T.F.); (R.C.)
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Gao K, Ma ZP, Zhang TL, Liu YW, Zhao YX. Comparative study of abdominal CT enhancement in overweight and obese patients based on different scanning modes combined with different contrast medium concentrations. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2024; 32:569-581. [PMID: 38217636 DOI: 10.3233/xst-230327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2024]
Abstract
PURPOSE To compare image quality, iodine intake, and radiation dose in overweight and obese patients undergoing abdominal computed tomography (CT) enhancement using different scanning modes and contrast medium. METHODS Ninety overweight and obese patients (25 kg/m2≤body mass index (BMI)< 30 kg/m2 and BMI≥30 kg/m2) who underwent abdominal CT-enhanced examinations were randomized into three groups (A, B, and C) of 30 each and scanned using gemstone spectral imaging (GSI) +320 mgI/ml, 100 kVp + 370 mgI/ml, and 120 kVp + 370 mgI/ml, respectively. Reconstruct monochromatic energy images of group A at 50-70 keV (5 keV interval). The iodine intake and radiation dose of each group were recorded and calculated. The CT values, contrast-to-noise ratios (CNRs), and subjective scores of each subgroup image in group A versus images in groups B and C were by using one-way analysis of variance or Kruskal-Wallis H test, and the optimal keV of group A was selected. RESULTS The dual-phase CT values and CNRs of each part in group A were higher than or similar to those in groups B and C at 50-60 keV, and similar to or lower than those in groups B and C at 65 keV and 70 keV. The subjective scores of the dual-phase images in group A were lower than those of groups B and C at 50 keV and 55 keV, whereas no significant difference was seen at 60-70 keV. Compared to groups B and C, the iodine intake in group A decreased by 12.5% and 13.3%, respectively. The effective doses in groups A and B were 24.7% and 25.8% lower than those in group C, respectively. CONCLUSION GSI +320 mgI/ml for abdominal CT-enhanced in overweight patients satisfies image quality while reducing iodine intake and radiation dose, and the optimal keV was 60 keV.
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Affiliation(s)
- Kai Gao
- Affiliated Hospital of Hebei University/Clinical Medical College, Hebei University, Baoding, China
| | - Ze-Peng Ma
- Affiliated Hospital of Hebei University/Clinical Medical College, Hebei University, Baoding, China
- Hebei Key Laboratory of Precise Imaging of Inflammation Related Tumors, Baoding, China
| | - Tian-Le Zhang
- Affiliated Hospital of Hebei University/Clinical Medical College, Hebei University, Baoding, China
- Hebei Key Laboratory of Precise Imaging of Inflammation Related Tumors, Baoding, China
| | - Yi-Wen Liu
- Affiliated Hospital of Hebei University/Clinical Medical College, Hebei University, Baoding, China
| | - Yong-Xia Zhao
- Affiliated Hospital of Hebei University/Clinical Medical College, Hebei University, Baoding, China
- Hebei Key Laboratory of Precise Imaging of Inflammation Related Tumors, Baoding, China
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Moradi H, Chehre H, Ghaderi B, Saghatchi F, Najafi M, Karami P, Rezaeejam H. Evaluating the Necessity and Radiation Risk of Brain CT Scans Requested by the Trauma Emergency Department. J Biomed Phys Eng 2023; 13:515-522. [PMID: 38148965 PMCID: PMC10749414 DOI: 10.31661/jbpe.v0i0.2012-1251] [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: 12/20/2020] [Accepted: 01/22/2021] [Indexed: 12/28/2023]
Abstract
Background Numerous Computed Tomography (CT) scan requests for trauma patients have raised serious concern about the impacts of radiation such as radiation-induced cancers. Objective This study aimed to evaluate the necessity rate of requested head CT scans for traumatic patients and to ultimately estimate the risk of radiation-induced brain cancer. Material and Methods In this retrospective analytical study, traumatic patients, who had undergone a head CT scan in a two-month period from August 23 to October 22, 2018, were considered as the study population. Two radiologists reviewed each patient individually to evaluate the rate of normal and abnormal cases. Dose length product in milligrays (mGy) was utilized to calculate the effective dose (ED) in millisieverts (mSv), resulting in an assessment of the risk of radiation-induced brain cancer using ICRP 103. Results Among 523 scans, 460 patients (88%) received normal reviews, while only 47 patients (9%) had findings related to their current trauma. The mean effective dose value was 1.05±0.36 mSv. Risk of the radiation induced brain cancer was calculated to be 0.037 and 0.030 new cancer cases in 10000 males and females per Gy, respectively. Conclusion Final results demonstrated that a significant number of traumatic patients undergoing a CT scan are in fact, healthy. Such reckless usage of CT and consequently the excess exposure could result in a dramatic rise in cancer rates. The need to limit unnecessary CT scan usage and keeping the radiation given to patients as low as reasonably achievable (ALARA) when collecting essential diagnostic data is more critical than ever.
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Affiliation(s)
- Hadi Moradi
- Student Research Committee, School of Paramedical Sciences, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Hossein Chehre
- Department of Biomedical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Behzad Ghaderi
- Department of Radiology, Mousavi Hospital, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Faranak Saghatchi
- Department of Radiology, School of Paramedical Sciences, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Masoud Najafi
- Department of Radiology, Mousavi Hospital, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Parisa Karami
- Department of Radiology, Mousavi Hospital, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Hamed Rezaeejam
- Department of Radiology, School of Paramedical Sciences, Zanjan University of Medical Sciences, Zanjan, Iran
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Bellizzi A, Bezzina P, Zarb F. Low dose CTPA using a low kV technique combined with high IR: A clinical study. Radiography (Lond) 2023; 29:738-744. [PMID: 37209581 DOI: 10.1016/j.radi.2023.05.001] [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: 02/07/2023] [Revised: 05/01/2023] [Accepted: 05/01/2023] [Indexed: 05/22/2023]
Abstract
INTRODUCTION To investigate optimising a computerised tomography pulmonary angiogram (CTPA) scan protocol in terms of radiation dose and image quality using a low kV technique combined with high iterative reconstruction (IR) parameters (>50%) and apply the optimised protocol in clinical practice on patients irrespective of their body weight. METHODS CTPA examinations were performed on 64 patients equally divided into control and experimental groups. Patients in the control group were scanned using the current protocol (100 kV with 50% IR) while patients in the experimental group were scanned using an optimised protocol (80 kV with 60%IR). The radiation dose indices volume computerised tomography dose index (CTDIvol), dose length product (DLP), size specific dose estimates (SSDE) and effective dose (ED) were recorded. Subjective image quality was evaluated by 3 radiologists through absolute visual grading analysis (VGA) using an image quality scoring tool. The resultant image quality scores were analysed using Visual Grading Characteristics (VGC). Objective image quality was recorded in terms of contrast-to-noise-ratio (CNR) and signal-to-noise-ratio (SNR). RESULTS The application of the optimised protocol resulted in a statistically significant (p < 0.05) reduction in mean CTDIvol (-49%), DLP (-48%), SSDE (-52%) and ED (-49%). Objective image quality was significantly (p < 0.05) improved both in CNR (32%) and SNR (13%). Subjective image quality scores were higher for the current protocol but variation between the two protocols was not significant (p = 0.650). CONCLUSIONS When applying the low kV technique combined with high IR parameters, a significant dose reduction may be achieved while still maintaining diagnostic image quality. IMPLICATIONS FOR PRACTICE The low kV technique combined with high IR parameters is an effective optimisation technique which can be easily implemented for the CTPA protocol.
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Affiliation(s)
- A Bellizzi
- Department of Radiography, Faculty of Health Sciences, University of Malta, Msida, Malta.
| | - P Bezzina
- Department of Radiography, Faculty of Health Sciences, University of Malta, Msida, Malta.
| | - F Zarb
- Department of Radiography, Faculty of Health Sciences, University of Malta, Msida, Malta.
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Agostini A, Borgheresi A, Mariotti F, Ottaviani L, Carotti M, Valenti M, Giovagnoni A. New frontiers in oncological imaging with Computed Tomography: from morphology to function. Semin Ultrasound CT MR 2023; 44:214-227. [DOI: 10.1053/j.sult.2023.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Bellizzi A, Bezzina P, Zarb F. Optimisation of the CT pulmonary angiogram (CTPA) protocol using a low kV technique combined with high iterative reconstruction (IR): A phantom study. Radiography (Lond) 2023; 29:313-318. [PMID: 36689833 DOI: 10.1016/j.radi.2022.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/16/2022] [Accepted: 11/27/2022] [Indexed: 01/22/2023]
Abstract
INTRODUCTION This study aims to optimise the current CTPA protocol at a public general hospital in Malta using lower kV combined with high Iterative Reconstruction (IR) (>50%). METHODS The research consisted of a 2-phase anthropomorphic phantom study. Phase 1: radiation dose evaluation of 6 experimental protocols consisting of the low kV technique and high IR values and comparison with the current protocol. Phase 2: image evaluation. Objective image quality was evaluated in terms of contrast to noise ratio (CNR) and signal to noise ratio (SNR). Subjective image quality evaluation was performed by 3 radiologists undertaking Absolute Visual Grading Analysis (VGA). Resultant image quality scores were analysed using Visual Grading Characteristics (VGC). RESULTS All experimental protocols achieved significant (p < 0.05) dose reductions. SNR and CNR improved in almost all protocols, however, differences were not significant (p > 0.05). In subjective image quality analysis, the current protocol provided significant superior image quality (AUC > 0.5; p < 0.05) when compared to the experimental protocols consisting of 80 kV with 70%, 80%, 90% and 100% IR. The only two experimental protocols yielding comparable image quality to the current protocol were 80 kV with 50% IR (AUC: 0.195; p: 0.137) and 80 kV with 60% IR (AUC: 0.554; p: 0.624). The protocol yielding the greatest decrease in radiation dose being 80 kV with 60% IR. CONCLUSIONS The optimal IR value was 60%. When applying the optimal experimental protocol (80 kV combined with 60% IR), a significant dose reduction was achieved while maintaining diagnostic image quality. IMPLICATIONS FOR PRACTICE The low kV technique combined with high IR parameter is easily implemented and involves no additional cost and equipment.
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Affiliation(s)
- A Bellizzi
- Department of Radiography, Faculty of Health Sciences, University of Malta, Msida, Malta.
| | - P Bezzina
- Department of Radiography, Faculty of Health Sciences, University of Malta, Msida, Malta.
| | - F Zarb
- Department of Radiography, Faculty of Health Sciences, University of Malta, Msida, Malta.
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Du Y, Wang YN, Wang Q, Qi XH, Shi GF, Jia LT, Wang XM, Shi JB, Liu FY, Wang LJ, Liu X. A comparison of the use of contrast media with different iodine concentrations for enhanced computed tomography. Front Physiol 2023; 14:1141135. [PMID: 37064921 PMCID: PMC10101225 DOI: 10.3389/fphys.2023.1141135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/03/2023] [Indexed: 04/18/2023] Open
Abstract
Objective: In this study, we compared the enhancement of blood vessels and liver parenchyma on enhanced computed tomography (CT) of the upper abdomen with two concentrations of contrast media (400 and 300 mg I/mL) based on similar iodine delivery rate (IDR) of 0.88 and 0.9 g I/s and iodine load of 450 mg I/kg. Methods: We randomly assigned 160 patients into two groups: iomeprol 400 mg I/mL (A group) and iohexol 300 mg I/mL (B group). The CT attenuation values of the main anatomical structures in the two groups with different scanning phases were measured and the image quality of the two groups was analyzed and compared. The peak pressure and local discomfort (including fever and pain) during contrast medium injection were recorded. Results: The mean attenuation value of the abdominal aorta was 313.6 ± 29.6 in the A group and 322.4 ± 30.1 in the B group during the late arterial phase (p = 0.8). Meanwhile, the mean enhancement values of the portal vein were 176.2 ± 19.3 and 165.9 ± 24.5 in the A and B groups, respectively, during the portal venous phase (p = 0.6). The mean CT values of liver parenchyma were 117.1 ± 15.3 and 108.8 ± 18.7 in the A and B groups, respectively, during the portal venous phase (p = 0.9). There was no statistical difference in image quality, peak injection pressure (psi), and local discomfort between the two groups (p > 0.05). Conclusion: When a similar IDR and the same iodine load are used, CT images with different concentrations of contrast media have the same subjective and objective quality, and can meet the diagnostic needs.
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Lortie J, Gage G, Rush B, Heymsfield SB, Szczykutowicz TP, Kuchnia AJ. The effect of computed tomography parameters on sarcopenia and myosteatosis assessment: a scoping review. J Cachexia Sarcopenia Muscle 2022; 13:2807-2819. [PMID: 36065509 PMCID: PMC9745495 DOI: 10.1002/jcsm.13068] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 06/21/2022] [Accepted: 07/20/2022] [Indexed: 12/15/2022] Open
Abstract
Computed tomography (CT) is a valuable assessment method for muscle pathologies such as sarcopenia, cachexia, and myosteatosis. However, several key underappreciated scan imaging parameters need consideration for both research and clinical use, specifically CT kilovoltage and the use of contrast material. We conducted a scoping review to assess these effects on CT muscle measures. We reviewed articles from PubMed, Scopus, and Web of Science from 1970 to 2020 on the effect of intravenous contrast material and variation in CT kilovoltage on muscle mass and density. We identified 971 articles on contrast and 277 articles on kilovoltage. The number of articles that met inclusion criteria for contrast and kilovoltage was 11 and 7, respectively. Ten studies evaluated the effect of contrast on muscle density of which nine found that contrast significantly increases CT muscle density (arterial phase 6-23% increase, venous phase 19-57% increase, and delayed phase 23-43% increase). Seven out of 10 studies evaluating the effect of contrast on muscle area found significant increases in area due to contrast (≤2.58%). Six studies evaluating kilovoltage on muscle density found that lower kilovoltage resulted in a higher muscle density (14-40% increase). One study reported a significant decrease in muscle area when reducing kilovoltage (2.9%). The use of contrast and kilovoltage variations can have dramatic effects on skeletal muscle analysis and should be considered and reported in CT muscle analysis research. These significant factors in CT skeletal muscle analysis can alter clinical and research outcomes and are therefore a barrier to clinical application unless better appreciated.
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Affiliation(s)
- Jevin Lortie
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Grace Gage
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Benjamin Rush
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Steven B Heymsfield
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | | | - Adam J Kuchnia
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
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Evaluating the Image Quality of Neck Structures Scanned on Chest CT with Low-Concentration-Iodine Contrast Media. Tomography 2022; 8:2854-2863. [PMID: 36548531 PMCID: PMC9785131 DOI: 10.3390/tomography8060239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/21/2022] [Accepted: 11/24/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The purpose of this study was to investigate and compare the image quality of low-concentration-iodine (240 mgI/mL) contrast media (CM) and high-concentration-iodine (320 mgI/mL) CM according to the radiation dose. METHODS A total of 366 CT examinations were examined. Based on an assessment of quantitative and qualitative parameters by two radiologists, the quality was compared between Group A (low-concentration-iodine CM) and Group B (high-concentration-iodine CM) images of thyroid gland, sternocleidomastoid muscle (SCM), internal jugular vein (IJV), and common carotid artery (CCA). Another subgroup analysis compared Group a, (using ≤90 kVp in Group A), and Group b, (using ≥100 kVp in Group B) for finding the difference in image quality when the tube voltage is lowered. RESULTS Image quality did not differ between Groups A and B or between Groups a and b. The signal-to-noise ratio and contrast-to-noise ratio were significantly higher for Group B than Group A for the thyroid gland, IJV, and CCA. No statistical differences were found in the comparison of all structures between Groups a and b. CONCLUSION There was no significant difference in image quality based on CM concentration with variable radiation doses. Therefore, if an appropriate CT protocol is applied, clinically feasible neck CT images can be obtained even using low-concentration-iodine CM.
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Evaluation of radiation exposure for patients undergoing computed tomography perfusion procedure for acute ischemic stroke. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Ladder-Like Low Iodine Delivery Rate Injection Protocols Based on BMI at 70 KV by Automated Tube Voltage Selection in Coronary CTA. CONTRAST MEDIA & MOLECULAR IMAGING 2022; 2022:7804015. [PMID: 35924071 PMCID: PMC9308544 DOI: 10.1155/2022/7804015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/31/2022] [Accepted: 06/07/2022] [Indexed: 11/17/2022]
Abstract
Objective To evaluate the feasibility of reducing the injection velocity and volume of contrast agent according to BMI, and the effect of body weight (BW), body surface area(BSA), body mass index(BMI),and blood volume (BV) on aortic contrast enhancement when the voltage of third-generation dual-source CT is selected at 70 KV. Methods A total of 280 patients selected at 70 KV were randomly divided into an experimental group and a control group. Each group was divided into 7 subgroups according to BMI ≤20, 20–21, 21-22, 22-23, 23-24, 24-25, and 25–26. The experimental group uses 2.3/2.4/2.5/2.6/2.7/2.8/2.9 ml/s injection speed with 350 mgI/ml contrast agents according to the subgroups; injection time was fixed at 10 s. In the control group, the fixed injection flow rate was 3.5 ml/s, time was 12 s with a total of 42 ml. Subjects in both groups were inspected to adaptive prospective ECG-gating sequence scanning, and subjective and objective image quality of the two groups were compared using Student's t-test. BMI, BSA, and BV were calculated from the patient's body weight and height. We assess the relationship between aortic attenuation and BW, BMI, BV, and BSA using regression analysis or correlation analysis. Results Significant differences exist in vascular enhancement between the two groups; SNR and CNR of objective image quality in the experimental group were lower than those in the control group (P < 0.05). Both groups had the same subjective image scores (P > 0.05). The number of vessels in the optimal enhancement range counts more in the experimental group than in the control group (χ2 value = 334.25, P < 0.05). In the control group, a weak to medium correlation was seen between vascular enhancement and BMI (r = −0.20), BW (r = −0.42), BSA (r = −0.46), and BV (r = −0.48) (P < 0.05 for all). Conclusions Compared to BW, BSA, and BV, a weaker negative correlation exists between vascular enhancement and BMI when ATVS selects 70 KV. However, as a much easier way to operate, the stepped low flow and low-contrast agent injection based on BMI was feasible, and the image quality was more homogenized than that of the control group.
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Chhetri S, Pendem S, Bharath J, Priyanka. Low kilovoltage and low contrast volume neck CT protocol using iterative reconstruction techniques: A comparison with standard dose protocol. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2021.109935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Dependence of the effective mass attenuation coefficient of gold nanoparticles on its radius. Phys Med 2022; 95:25-31. [DOI: 10.1016/j.ejmp.2022.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 01/03/2022] [Accepted: 01/17/2022] [Indexed: 11/24/2022] Open
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Recommendations in pre-procedural imaging assessment for TAVI intervention: SIC-SIRM position paper part 2 (CT and MR angiography, standard medical reporting, future perspectives). LA RADIOLOGIA MEDICA 2022; 127:277-293. [PMID: 35129758 DOI: 10.1007/s11547-021-01434-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 11/16/2021] [Indexed: 10/19/2022]
Abstract
Non-invasive cardiovascular imaging owns a pivotal role in the preoperative assessment of patient candidates for transcatheter aortic valve implantation (TAVI), providing a wide range of crucial information to select the patients who will benefit the most and have the procedure done safely. This document has been developed by a joined group of experts of the Italian Society of Cardiology and the Italian Society of Medical and Interventional Radiology and aims to produce an updated consensus statement about the pre-procedural imaging assessment in candidate patients for TAVI intervention. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac and vascular radiology. Part 2 of the document will cover CT and MR angiography, standard medical reporting, and future perspectives.
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15
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Tekin E, Tuncer K, Ozlu I, Sade R, Pirimoglu RB, Polat G. Ultra-low-dose computed tomography and its utility in wrist trauma in the emergency department. Acta Radiol 2022; 63:192-199. [PMID: 33508953 DOI: 10.1177/0284185121989958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND The use and frequency of computed tomography (CT) are increasing day by day in emergency departments (ED). This increases the amount of radiation exposed. PURPOSE To evaluate the image quality obtained by ultra-low-dose CT (ULDCT) in patients with suspected wrist fractures in the ED and to investigate whether it is an alternative to standard-dose CT (SDCT). MATERIAL AND METHODS This is a study prospectively examining 336 patients who consulted the ED for wrist trauma. After exclusion criteria were applied, the patients were divided into the study and control groups. Then, SDCT (120 kVp and 100 mAs) and ULDCT (80 kVp and 5 mAs) wrist protocols were applied simultaneously. The images obtained were evaluated for image quality and fracture independently by a radiologist and an emergency medical specialist using a 5-point scale. RESULTS The effective radiation dose calculated for the control group scans was 41.1 ± 2.1 µSv, whereas the effective radiation dose calculated for the study group scans was 0.5 ± 0.0 µSv. The effective radiation dose of the study group was significantly lower than that of the control group (P < 0.01). The CT images in the study group showed no significant differences in the mean image quality score between observer 1 and observer 2 (3.4 and 4.3, respectively; P = 0.58). Both observers could detect all fractures using the ULDCT images. CONCLUSION ULDCT provides high-quality images in wrist traumas while reducing the radiation dose by approximately 98% compared to SDCT without any changes in diagnostic accuracy.
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Affiliation(s)
- Erdal Tekin
- Department of Emergency Medicine, Ataturk University Faculty of Medicine, Erzurum, Turkey
| | - Kutsi Tuncer
- Department of Orthopedics and Traumatology, Ataturk University Faculty of Medicine, Erzurum, Turkey
| | - Ibrahim Ozlu
- Department of Emergency Medicine, Ataturk University Faculty of Medicine, Erzurum, Turkey
| | - Recep Sade
- Department of Radiology, Medical Faculty, Ataturk University, Erzurum, Turkey
- Clinical Research, Development and Design Application and Research Center, Ataturk University, Erzurum, Turkey
| | | | - Gokhan Polat
- Department of Radiology, Medical Faculty, Ataturk University, Erzurum, Turkey
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Effect of Body Mass Index in Coronary CT Angiography Performed on a 256-Slice Multi-Detector CT Scanner. Diagnostics (Basel) 2022; 12:diagnostics12020319. [PMID: 35204410 PMCID: PMC8871507 DOI: 10.3390/diagnostics12020319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/18/2022] [Accepted: 01/24/2022] [Indexed: 12/21/2022] Open
Abstract
We aimed to investigate the effect of a patient’s body mass index (BMI) on radiation dose and image quality in prospectively ECG-triggered coronary CT angiography (CCTA) performed on a 256-slice multi-detector CT scanner. In total, 87 consecutive patients receiving CCTA examinations acquired with tube current modulation (TCM) and iterative reconstruction (IR) were enrolled in this study. The dose report recorded from the CT scanner console was used to derive the effective dose for patients. Subjective image quality scoring and objective noise measurements were conducted to quantify the impact of BMI on the image quality of CCTA. Because of the TCM technique, we expected tube current and radiation dose to increase as BMI increased. However, using TCM did not always guarantee sufficient radiation exposure to achieve consistent image quality for overweight or obese patients since the maximum X-ray tube output in milliamperes and kilovoltage peak was reached. The impact of photon starvation noise on image quality was not significant until BMI ≥ 27 kg/m2; this result could be due to IR’s noise reduction capability. Our results also suggest that using TCM with a noise index of 25 HU can reduce radiation dose without compromising image quality compared to images obtained based on the manufacturer’s default settings.
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Bos D, Zensen S, Opitz M, Haubold J, Forsting M, Nassenstein K, Guberina N, Wetter A. IMAGE QUALITY STUDY OF RADIATION-REDUCED COMBINED CHEST AND ABDOMEN/PELVIS CT COMPARED WITH A STANDARD PROTOCOL. RADIATION PROTECTION DOSIMETRY 2021; 196:190-198. [PMID: 34635920 DOI: 10.1093/rpd/ncab147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 09/10/2021] [Accepted: 09/15/2021] [Indexed: 06/13/2023]
Abstract
The purpose of this study is to examine radiation doses and image quality of a low-dose (LD) protocol for chest and abdomen/pelvis (CAP) CT compared with a standard (STD) protocol. A total of 361 patients were included between October 2019 and April 2020; 104 patients with LD-protocol (100 kV, ref mAs 80 (chest)/145 (abdomen/pelvis)) and 257 patients with STD-protocol (100 kV, ref mAs 100 (chest)/180 (abdomen/pelvis)) at second-generation dual-source CT. Radiation doses for CTDIvol and DLP, and objective and subjective image qualities of 50 examinations from each group were evaluated. The LD-protocol applied significantly lower radiation doses compared with the STD-protocol (p < 0.001), achieving a dose reduction by 37% for the median DLP in chest, 19% in abdomen/pelvis and 22% in total. Median total DLP was 342 mGy·cm (LD) vs. 436 mGy·cm (STD). The LD-CAP CT protocol achieved a significant dose reduction far below national diagnostic reference levels, ensuring acceptable and good image quality.
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Affiliation(s)
- Denise Bos
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45147 Essen, Germany
| | - Sebastian Zensen
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45147 Essen, Germany
| | - Marcel Opitz
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45147 Essen, Germany
| | - Johannes Haubold
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45147 Essen, Germany
| | - Michael Forsting
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45147 Essen, Germany
| | - Kai Nassenstein
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45147 Essen, Germany
| | - Nika Guberina
- Department of Radiotherapy, West German Cancer Center, University Hospital Essen, Hufelandstrasse 55, 45147 Essen, Germany
| | - Axel Wetter
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45147 Essen, Germany
- Department of Diagnostic and Interventional Radiology, Neuroradiology, Asklepios Klinikum Harburg, Eißendorfer Pferdeweg 52, 21075 Hamburg, Germany
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18
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Zhang Q, Mi H, Shi X, Li W, Guo S, Wang P, Suo H, Wang Z, Jin S, Yan F, Niu Y, Xian J. Higher Iodine Concentration Enables Radiation Dose Reduction in Coronary CT Angiography. Acad Radiol 2021; 28:1072-1080. [PMID: 32553279 DOI: 10.1016/j.acra.2020.05.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/13/2020] [Accepted: 05/13/2020] [Indexed: 01/01/2023]
Abstract
RATIONALE AND OBJECTIVES To test whether higher iodine concentration together with higher noise level could lead to a further dose reduction in an already low dose coronary CT angiography (CCTA) protocol without comprising image quality. MATERIALS AND METHODS One hundred eighty patients with suspected coronary artery disease (CAD) were randomly assigned into three groups: (a) conventional dose (CD) group, 100 kV with a noise index (NI) of 25 and iohexol (350 mg I/ml); (b) low dose (LD) group, 80 kV with a NI of 25 and iohexol (350 mg I/ml); (c) further low dose (FLD) group, 80 kV with a NI of 30 and iomeprol (400 mg I/ml). The volume and injection rate of contrast medium were fixed at 60 ml and 5 ml/s. The radiation dose (volume CT dose index [CTDIvol], dose length product [DLP], and effective dose [ED]) were recorded. For image quality, both quantitative (enhancement, noise, signal-to-noise ratio [SNR], and contrast-to-noise ratio [CNR]) and qualitative indices were assessed. RESULTS Compared to the CD group, ED was reduced by 16% and 42% in the LD and FLD groups, respectively (p < 0.05). Qualitative analysis showed no significant difference among the 3 groups (p > 0.05), while quantitative analysis revealed significantly higher attenuation in the LD and FLD groups. Signal-to-noise ratios and CNRs of the LD and FLD groups were significantly higher except for the CNR at the left circumflex branch of the FLD group (p < 0.05). CONCLUSION Increasing iodine concentration and noise level may further reduce the radiation dose by 26% on top of a 16% reduction from 100 kV to 80 kV without image quality compromise.
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Affiliation(s)
- Qing Zhang
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaomin lane, Dongcheng District, Beijing 100730, P.R. China
| | - Haifeng Mi
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaomin lane, Dongcheng District, Beijing 100730, P.R. China
| | - Xubo Shi
- Department of Cardiology, Beijing Tongren Hospital, Capital Medical University, Beijing, P.R. China
| | - Wei Li
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaomin lane, Dongcheng District, Beijing 100730, P.R. China
| | - Senlin Guo
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaomin lane, Dongcheng District, Beijing 100730, P.R. China
| | - Ping Wang
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaomin lane, Dongcheng District, Beijing 100730, P.R. China
| | - Hongna Suo
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaomin lane, Dongcheng District, Beijing 100730, P.R. China
| | - Ziyi Wang
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaomin lane, Dongcheng District, Beijing 100730, P.R. China
| | - Shanshan Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, P.R. China
| | - Fei Yan
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaomin lane, Dongcheng District, Beijing 100730, P.R. China
| | - Yantao Niu
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaomin lane, Dongcheng District, Beijing 100730, P.R. China
| | - Junfang Xian
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaomin lane, Dongcheng District, Beijing 100730, P.R. China.
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19
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Johansen CB, Martinsen ACT, Enden TR, Svanteson M. The potential of iodinated contrast reduction in dual-energy CT thoracic angiography; an evaluation of image quality. Radiography (Lond) 2021; 28:2-7. [PMID: 34301491 DOI: 10.1016/j.radi.2021.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 10/20/2022]
Abstract
INTRODUCTION The purpose of this study was to compare a dual energy CT (DECT) protocol with 50% reduction of iodinated contrast to a single energy CT (SECT) protocol using standard contrast dose in imaging of the thoracic aorta. METHODS DECT with a 50% reduction in iodinated contrast was compared with SECT. For DECT, monoenergetic images at 50, 55, 60, 65, 68, 70, and 74 keV were reconstructed with adaptive statistical iterative reconstruction (ASiR-V) of 50% and 80%. Objective image quality parameters included intravascular attenuation (HU), image noise (SD), contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR). Two independent radiologists subjectively assessed the image quality for the 55 and 68 keV DECT reconstructions and SECT on a five-point Likert scale. RESULTS Across 14 patients, the intravascular attenuation at 50-55 keV was comparable to SECT (p > 0.05). The CNRs were significantly lower for DECT with ASIR-V 50% compared to SECT for all keV-values (p < 0.05 for all). For ASIR-V 80%, CNR was comparable to SECT at energies below 60 keV (p > 0.05). The subjective image quality was comparable between DECT and SECT independent of keV level. CONCLUSION This study indicates that a 50% reduction in iodinated contrast may result in adequate image quality using DECT with monoenergetic reconstructions at lower energy levels for the imaging of the thoracic aorta. The best image quality was obtained for ASiR-V 80% image reconstructions at 55 keV. IMPLICATIONS OF PRACTICE Dual energy CT with a reduction in iodinated contrast may result in adequate image quality in imaging of the thoracic aorta. However, increased radiation dose may limit the use to patients in which a reduction in fluid and iodinated contrast volume may outweigh this risk.
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Affiliation(s)
- C B Johansen
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norway; Faculty of Health Science, Oslo Metropolitan University, Norway.
| | - A C T Martinsen
- Faculty of Health Science, Oslo Metropolitan University, Norway; Sunnaas Rehabilitation Hospital, Norway.
| | - T R Enden
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norway.
| | - M Svanteson
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norway; ImTECH, Department of Diagnostic Physics, Oslo University Hospital, Norway.
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20
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Shwaiki O, Rashwan B, Fink MA, Kirksey L, Gadani S, Karuppasamy K, Melzig C, Thompson D, D'Amico G, Rengier F, Partovi S. Lower extremity CT angiography in peripheral arterial disease: from the established approach to evolving technical developments. Int J Cardiovasc Imaging 2021; 37:3101-3114. [PMID: 33997924 DOI: 10.1007/s10554-021-02277-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/03/2021] [Indexed: 12/13/2022]
Abstract
With the advent of multidetector computed tomography (CT), CT angiography (CTA) has gained widespread popularity for noninvasive imaging of the arterial vasculature. Peripheral extremity CTA can nowadays be performed rapidly with high spatial resolution and a decreased amount of both intravenous contrast and radiation exposure. In patients with peripheral artery disease (PAD), this technique can be used to delineate the bilateral lower extremity arterial tree and to determine the amount of atherosclerotic disease while differentiating between acute and chronic changes. This article provides an overview of several imaging techniques for PAD, specifically discusses the use of peripheral extremity CTA in patients with PAD, clinical indications, established technical considerations and novel technical developments, and the effect of postprocessing imaging techniques and structured reporting.
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Affiliation(s)
- Omar Shwaiki
- Department of Interventional Radiology, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - Basem Rashwan
- Department of Interventional Radiology, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - Matthias A Fink
- Section of Emergency Radiology, Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Levester Kirksey
- Department of Vascular Surgery, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - Sameer Gadani
- Department of Interventional Radiology, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | | | - Claudius Melzig
- Section of Emergency Radiology, Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Dustin Thompson
- Department of Interventional Radiology, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - Giuseppe D'Amico
- Department of Transplant Surgery, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - Fabian Rengier
- Section of Emergency Radiology, Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Sasan Partovi
- Department of Interventional Radiology, Cleveland Clinic Main Campus, Cleveland, OH, USA.
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21
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Zawam Dalah E, Dhou S, Mudalige T, Amin F, Obaideen A. Challenges estimating patient organs doses undergoing enhanced chest CT examination: exploratory study. Biomed Phys Eng Express 2021; 7. [PMID: 33588398 DOI: 10.1088/2057-1976/abe68e] [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: 11/23/2020] [Accepted: 02/15/2021] [Indexed: 11/11/2022]
Abstract
Purpose: Estimate organs doses (ODs) of patients subjected to unenhanced (S1) and enhanced (S2) chest CT studies relying on image parameters such as Hounsfield Units (HUs).Materials and Methods: CT scans and images of a total of 16 patients who underwent two series of chest CT studies were obtained and retrospectively examined. OD increments of liver and pancreas for both series (S1 & S2) were estimated using two different independent methods, namely simulation approach using CT-EXPO and Amato's phantom-based fitting model (APFM). HUs were quantified for each organ by manually drawing fixed area-sized regions of interest (ROIs). The mean HUs were collected to obtain the ODs increments following APFM. Regression analysis was applied to find and assess the relationship between the HUs and the OD increments estimated using APFM and that using CT-EXPO. Spearman Coefficient and Wilcoxon Matched Pairedt-testwere conducted to show statistical correlation and difference between ODs increments using the two methods.Results:A strong significant difference was depicted between S1 and S2 scan series of liver and pancreas using CT-EXPO simulation. Mean HU values for S1 were lower than S2, resulting in statistically significant (p < 0.0001) HU changes. CT-EXPO simulation yielded significantly higher difference in ODs compared to the APFM for liver (p = 0.0455) and pancreas (p = 0.0031). Regression analysis revealed a strong relationship between HU of S1 and S2 and ODs increments using APFM in both organs (R2 = 0.99), dissimilar to CT-EXPO (R2 = 0.39 in liver andR2 = 0.05 in pancreas).Conclusions: Although CT-EXPO allows for estimating ODs accounting for major acquisition scan parameters, it is not a reliable tool to evaluate the impact of contrast enhancement on ODs. On the other hand, the APFM accounts for contrast enhancement accumulation yet only provides relative OD increments, an information of limited clinical use.
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Affiliation(s)
- Entesar Zawam Dalah
- Department of Clinical Support Services and Nursing Sector, Dubai Health Authority, Dubai, UAE.,Department of Medical Diagnostic Imaging, University of Sharjah, Sharjah, UAE
| | - Salam Dhou
- Department of Computer Science and Engineering, American University of Sharjah, Sharjah, UAE
| | - Thilini Mudalige
- Department of Medical Diagnostic Imaging, University of Sharjah, Sharjah, UAE
| | - Fatima Amin
- Department of Medical Diagnostic Imaging, University of Sharjah, Sharjah, UAE
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22
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Feasibility of Low Volume of High-Concentration Iodinated Contrast Medium With 70 kVp Tube Voltage on High-Pitch Dual-Source Computed Tomography Angiography in Children With Congenital Heart Disease. J Comput Assist Tomogr 2021; 45:52-58. [PMID: 32740051 DOI: 10.1097/rct.0000000000001033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The objective of this study was to investigate the feasibility of high-concentration iodinated contrast medium (CM) with 70 kVp tube voltage on high-pitch dual-source computed tomography (DSCT) in children with congenital heart disease (CHD). METHODS Fifty-eight CHD patients underwent high-pitch DSCT in 2 protocols: 70 kVp tube voltage, 1.0 mL/kg CM volume, 370 mg I/mL concentration (group A); 80 kVp tube voltage, 1.5 mL/kg CM volume, 350 mg I/mL concentration (group B). The diagnostic accuracy, image quality, iodine delivery rate, iodine dose, and radiation dose were compared. RESULTS There was no significant difference in the diagnostic accuracy (P > 0.05), image quality (P > 0.05) and iodine delivery rate (P > 0.05) between the 2 groups. The iodine dose (P < 0.05) and radiation dose (P < 0.05) in group A were significantly lower than those in group B. CONCLUSIONS Reduction in iodine dose and radiation exposure can be achieved with 70 kVp high-pitch DSCT by administering a smaller volume of high-concentration CM in children with CHD.
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23
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Solbak MS, Henning MK, England A, Martinsen AC, Aaløkken TM, Johansen S. Impact of iodine concentration and scan parameters on image quality, contrast enhancement and radiation dose in thoracic CT. Eur Radiol Exp 2020; 4:57. [PMID: 32915405 PMCID: PMC7486352 DOI: 10.1186/s41747-020-00184-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/12/2020] [Indexed: 12/11/2022] Open
Abstract
Background We investigated the impact of varying contrast medium (CM) densities and x-ray tube potentials on contrast enhancement (CE), image quality and radiation dose in thoracic computed tomography (CT) using two different scanning techniques. Methods Seven plastic tubes containing seven different CM densities ranging from of 0 to 600 HU were positioned inside a commercial chest phantom with padding, representing three different patient sizes. Helical scans of the phantom in single-source mode were obtained with varying tube potentials from 70 to 140 kVp. A constant volume CT dose index (CTDIvol) depending on phantom size and automatic dose modulation was tested. CE (HU) and image quality (contrast-to-noise ratio, CNR) were measured for all combinations of CM density and tube potential. A reference threshold of CE and kVp was defined as ≥ 200 HU and 120 kVp. Results For the medium-sized phantom, with a specific CE of 100–600 HU, the diagnostic CE (200 HU) at 70 kVp was ~ 90% higher than at 120 kVp, for both scan techniques (p < 0.001). Changes in CM density/specific HU together with lower kVp resulted in significantly higher CE and CNR (p < 0.001). When changing only the kVp, no statistically significant differences were observed in CE or CNR (p ≥ 0.094), using both dose modulation and constant CTDIvol. Conclusions For thoracic CT, diagnostic CE (≥ 200 HU) and maintained CNR were achieved by using lower CM density in combination with lower tube potential (< 120 kVp), independently of phantom size.
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Affiliation(s)
- Marian S Solbak
- Faculty of Health Sciences, Oslo Metropolitan University, Pilestredet 48, 0130, Oslo, Norway
| | - Mette K Henning
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Andrew England
- School of Allied Health Professions, Keele University, Staffordshire, England
| | - Anne C Martinsen
- Faculty of Health Sciences, Oslo Metropolitan University, Pilestredet 48, 0130, Oslo, Norway.,Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Trond M Aaløkken
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.,Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Safora Johansen
- Faculty of Health Sciences, Oslo Metropolitan University, Pilestredet 48, 0130, Oslo, Norway. .,Department of Cancer Treatment, Oslo University Hospital, Oslo, Norway.
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24
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Iyer VR, Ehman EC, Khandelwal A, Wells ML, Lee YS, Weber NM, Johnson MP, Yu L, McCollough CH, Fletcher JG. Image quality in abdominal CT using an iodine contrast reduction algorithm employing patient size and weight and low kV CT technique. Acta Radiol 2020; 61:1186-1195. [PMID: 31986894 DOI: 10.1177/0284185119898655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Low tube potential-high tube current computed tomography (CT) imaging allows reduction in iodine-based contrast dose and may extend the benefit of routine contrast-enhanced CT exams to patients at risk of nephrotoxicity. PURPOSE To determine the ability of an iodine contrast reduction algorithm to maintain diagnostic image quality for contrast-enhanced abdominal CT. MATERIAL AND METHODS CT exams with iodine contrast reduction were prescribed for patients at risk for renal dysfunction. The iodine contrast reduction algorithm combines weight-based contrast volume reduction with patient width-based low tube potential selection and bolus-tracking. Control exams with routine iodine dose were selected based on weight, width, and scan protocol. Three radiologists evaluated image quality and diagnostic confidence using a 4-point scale (<2 acceptable). Another radiologist assessed contrast reduction indications and measured portal vein and liver contrast-to-noise ratios. RESULTS Forty-six contrast reduction algorithm and control exams were compared (mean creatinine 1.6 vs. 1.2 mg/dL, P ≤ 0.0001). Thirty-nine contrast reduction patients had an eGFR <60 mL/min/1.73m2 and 15 had single or transplanted kidney. Mean iodine contrast dose was lower in the contrast reduction group (20.9 vs. 39.4 g/mL, P < 0.0001). Diagnostic confidence was rated as acceptable in 95% (131/138) of contrast reduction and 100% of control exams (1.18-1.28 vs. 1.02-1.13, respectively; P > 0.06). Liver attenuation and contrast-to-noise ratio (CNR) were similar (P = 0.08), but portal vein attenuation and CNR were lower with contrast-reduction (mean 176 vs. 198 HU, P = 0.02; 13 vs. 16, P = 0.0002). CONCLUSION This size-based contrast reduction algorithm using low kV and bolus tracking reduced iodine contrast dose by 50%, while achieving acceptable image quality in 95% of exams.
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Affiliation(s)
- Veena R Iyer
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Eric C Ehman
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | | | | | - Yong S Lee
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | | | - Matthew P Johnson
- Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA
| | - Lifeng Yu
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
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25
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Comparing feasibility of low-tube-voltage protocol with low-iodine-concentration contrast and high-tube-voltage protocol with high-iodine-concentration contrast in coronary computed tomography angiography. PLoS One 2020; 15:e0236108. [PMID: 32673356 PMCID: PMC7365455 DOI: 10.1371/journal.pone.0236108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 06/29/2020] [Indexed: 11/19/2022] Open
Abstract
Background To investigate the feasibility of a low tube voltage (80 kVp) protocol with low concentration contrast media (CM) (iodixanol 320 mgl/ml) as compared with a high tube voltage (100 kVp) protocol with high concentration CM (iomeprol 400 mgl/ml) in coronary CT angiography (CCTA) for patients with body mass index less than 30. Materials and methods A total of 93 patients were randomly assigned into three groups and underwent CCTA as follows: Group A) 100 kVp, 100–350 mAs, 400 mgl/ml CM at 4ml/s, and reconstructed with filtered back projection; Group B and C) 80 kVp, 100–450 mAs, 320 mgl/ml CM at 4 ml/s and 5 ml/s, respectively and reconstructed with iterative reconstruction. Objective and subjective image quality (IQ) was analyzed. Results The image noise, intravascular attenuation, signal-to-noise ratio and contrast-to-noise ratio of major coronary arteries did not differ significantly among three groups. Subjective IQ analyses on vascular attenuation and image noise did not differ significantly, either (all of p > 0.05). Qualitative IQ of Group B and C was non-inferior to that of Group A. Substantial reduction of radiation exposure was achieved in group B (2.60 ± 0.48 mSv) and C (2.72 ± 0.54 mSv), compared with group A (3.58 ± 0.67 mSv) (p < 0.05). Conclusion CCTA at 80 kVp with 320 mgl/ml CM and iterative reconstruction is feasible, achieving radiation dose reduction, while preserving IQ.
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McDermott M, Kemper C, Barone W, Jost G, Endrikat J. Impact of CT Injector Technology and Contrast Media Viscosity on Vascular Enhancement: Evaluation in a Circulation Phantom. Br J Radiol 2020; 93:20190868. [PMID: 32017607 PMCID: PMC7217576 DOI: 10.1259/bjr.20190868] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Objective: To assess the impact of piston-based vs peristaltic injection system technology and contrast media viscosity on achievable iodine delivery rates (IDRs) and vascular enhancement in a pre-clinical study. Methods: Four injectors were tested: MEDRAD® Centargo, MEDRAD® Stellant, CT Exprès®, and CT motion™ using five contrast media [iopromide (300 and 370 mgI ml−1), iodixanol 320 mgI ml−1, iohexol 350 mgI ml−1, iomeprol 400 mgI ml−1]. Three experiments were performed evaluating achievable IDR and corresponding enhancement in a circulation phantom. Results: Experiment I: Centargo provided the highest achievable IDRs with all tested contrast media (p < 0.05). Iopromide 370 yielded the highest IDR with an 18G catheter (3.15 gI/s); iopromide 300 yielded the highest IDR with 20G (2.70 gI/s) and 22G (1.65 gI/s) catheters (p < 0.05). Experiment II: with higher achievable IDRs, piston-based injectors provided significantly higher peak vascular enhancement (up to 48% increase) than the peristaltic injectors with programmed IDRs from 1.8 to 2.4 gI/s (p < 0.05). Experiment III: with programmed IDRs (e.g. 1.5 gI/s) achievable by all injection systems, Centargo, with sharper measured bolus shape, provided significant increases in enhancement of 34–73 HU in the pulmonary artery with iopromide 370 (p < 0.05). Conclusion: The tested piston-based injection systems combined with low viscosity contrast media provide higher achievable IDRs and higher peak vascular enhancement than the tested peristaltic-based injectors. With equivalent IDRs, Centargo provides higher peak vascular enhancement due to improved bolus shape. Advances in knowledge: This paper introduces a new parameter to compare expected performance among contrast media: the concentration/viscosity ratio. Additionally, it demonstrates previously unexplored impacts of bolus shape on vascular enhancement.
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Affiliation(s)
- Michael McDermott
- Bayer U.S. LLC, Bayer Pharmaceuticals, Radiology R&D, Indianola, PA 15051, USA
| | - Corey Kemper
- Bayer U.S. LLC, Bayer Pharmaceuticals, Radiology R&D, Indianola, PA 15051, USA
| | - William Barone
- Bayer U.S. LLC, Bayer Pharmaceuticals, Radiology R&D, Indianola, PA 15051, USA
| | - Gregor Jost
- Bayer AG, MR & CT Contrast Media Research, Berlin, Germany
| | - Jan Endrikat
- Bayer AG, Radiology R&D, 13353 Berlin, Germany.,Department of Gynecology, Obstetrics and Reproductive Medicine, University Medical School of Saarland, 66421 Homburg/Saar, Germany
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Karout L, El Asmar K, Naffaa L, Abi-Ghanem AS, El-Merhi F, Salman R, Saade C. Balancing act between quantitative and qualitative image quality between nonionic iodinated dimer and monomer at various vessel sizes during computed tomography: a phantom study. Biomed Phys Eng Express 2020; 6:035001. [PMID: 33438646 DOI: 10.1088/2057-1976/ab78dc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE Investigate the impact of nonionic dimer and monomer on iodine quantification in different vessel sizes when employing a vascular specific phantom and varying iodinated contrast media (ICM) concentrations during computed tomography (CT). MATERIALS AND METHODS We created a vascular specific phantom (30 cm) to simulate human blood vessel diameters (25 cylinders of different diameters: 10 × 9mm, 10 × 12mm and 5 × 21mm). The phantom was filled with two ICM separately: Group: Iohexol(monomer)350 mg ml-1 and B: Iodixanol(Dimer)320 mg ml-1. Cylinders of same size were filled with increasing ICM concentration(10%-100%) while large cylinders were filled in quartiles(25%-100%). Phantom was scanned with different tube potential (80-140kVp), current (50-400mAs), reconstruction method [filtered back projection (FBP), hybrid-based iterative reconstruction (HBIR) and model-based iterative reconstruction (MBIR)] for each ICM. Chi-square was employed to compare mean opacification, contrast/noise ratio (CNR) and noise. Qualitative analysis was assessed by Visual grading characteristic (VGC) and Cohens-kappa analyses. RESULTS At 80 and140kVp significant difference in opacification between Group A (2054 ± 1040HU and 1696 ± 1027HU) and B (2169 ± 1105HU and 1568 ± 1034HU) was demonstrated (p < 0.001). However, at 100 and 120kVp no difference was noted (p > 0.05). When comparing image noise, it was higher in Group A compared to B (p < 0.05). CNR was higher in Group B (119.99 ± 126.10HU) than A (107.09 ± 102.56HU) (p < 0.0001). VGC: Group A outperformed B in image opacification in all vessel sizes and ICM concentrations except at medium vessels with concentration group 2(0.4-0.6 mg ml-1). Cohens'-kappa: agreement in opacification between each ICM group and iodine concentration 1(0-0.3 mg ml-1): κ = 0.253 and 0.014 respectively, concentration 2(0.4-0.6 mg ml-1):κ = -0.017 and -0.005 respectively and concentration 3(0.7-1 mg ml-1):κ = 0.031 and 0.115 respectively. CONCLUSION Nonionic dimer (Iodixanol) surpasses monomer (Iohexol) in quantitative image quality assessment by having lower image noise and higher CNR during CT.
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Affiliation(s)
- Lina Karout
- Diagnostic Radiology Department, American University of Beirut Medical Center, Beirut, American University of Beirut Medical Center, Beirut, Lebanon. P O Box: 11-0236 Riad El-Solh, Beirut, 1107 2020, Lebanon
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Eichler M, May M, Wiesmueller M, Saake M, Heiss R, Uder M, Wuest W. Single source split filter dual energy: Image quality and liver lesion detection in abdominal CT. Eur J Radiol 2020; 126:108913. [PMID: 32135408 DOI: 10.1016/j.ejrad.2020.108913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 12/23/2019] [Accepted: 02/18/2020] [Indexed: 10/25/2022]
Abstract
PURPOSE Aim of this study was to evaluate image quality of single source dual energy CT (SSDE-CT) using split filter technique in oncologic abdominal CT. METHOD 51 consecutive patients with newly diagnosed breast carcinoma were prospectively enrolled in this study and underwent a staging examination of the abdomen using SSDE-CT (120 kV, split filter technique, 400 ref. mAs). Inline default images (DI) and post-processed virtual monoenergetic images at 40 keV, 50 keV, 60 keV, 70 keV and 80 keV were reconstructed. Objective image quality was evaluated as contrast to noise ratio (CNR) for liver parenchyma, portal vein, spleen, pancreas, aorta and hypoattenuating liver lesions. Subjective image quality was rated on a 5-point scale. Image quality at different keV settings was analyzed in paired t-tests. RESULTS CNR was highest at 40 keV for vessels (portal vein: 9.0, aorta: 8.8, all p < 0.001) and for upper abdominal organs (spleen: 4.8, all p < 0.001; pancreas: 2.7, all p < 0.01 except p = 0.93 for 50 keV; liver parenchyma: 3.4, all p < 0.01). Highest CNR values for hypoattenuating liver lesions were found at 40 keV (7.7, all p < 0.001). Overall subjective image quality was highest with 80 keV and DI (both 4.8, all p < 0.001). Artifacts were most pronounced at 40 keV. CONCLUSIONS High image quality can be obtained with SSDE-CT of the abdomen. Lowest monoenergetic reconstructions provide the highest image contrast and should be used for vessel evaluation. The best trade-off between artifacts and parenchymal contrast can be obtained with 80 keV images.
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Affiliation(s)
- Mathis Eichler
- Radiological Institute Friedrich-Alexander-University-Erlangen-Nuremberg, Germany.
| | - Matthias May
- Radiological Institute Friedrich-Alexander-University-Erlangen-Nuremberg, Germany.
| | - Marco Wiesmueller
- Radiological Institute Friedrich-Alexander-University-Erlangen-Nuremberg, Germany.
| | - Marc Saake
- Radiological Institute Friedrich-Alexander-University-Erlangen-Nuremberg, Germany.
| | - Rafael Heiss
- Radiological Institute Friedrich-Alexander-University-Erlangen-Nuremberg, Germany.
| | - Michael Uder
- Radiological Institute Friedrich-Alexander-University-Erlangen-Nuremberg, Germany.
| | - Wolfgang Wuest
- Radiological Institute Friedrich-Alexander-University-Erlangen-Nuremberg, Germany.
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Hsiao CC, Chen PC, Kuo PC, Ho CH, Jao JC. Assessment of image quality and dose in contrast-enhanced head and neck CT angiography of New Zealand rabbit. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2020; 28:739-750. [PMID: 32597826 DOI: 10.3233/xst-200669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
BACKGROUND Although computed tomography (CT) is a powerful diagnostic imaging modality for diagnosing vascular diseases, it is some what risky to human health due to the high radiation dosage. Thus, CT vendors have developed low dose computed tomography (LDCT) aiming to solve this problem. Nowadays, LDCT has gradually become a main stream of CT examination. OBJECTIVE This study aimed to assess the feasibility of LDCTAin an animal model and compare the imaging features and doses in two clinical scanners. METHODS Twenty-two New Zealand rabbit head and neck CTA images pre- and post-contrast agent injection were performed using256-sliceand 64-slice CT scanners. The tube voltages used in the 256-slice and the 64-slice CTA were 70 kVp and 80 kVp, respectively. Quantitative images indices and radiation doses obtained from CTA in these two scanners were compared. RESULTS More neck arterial vessels could be visualized in multi-planar reconstruction (MPR) CTA on the 256-slice CT scanner than on the 64-slice CT scanner. After contrast agent injection, all observed neck arterial vessels had higher CT numbers in 256-slice CTA than in 64-slice CTA. There was no significant difference in contrast-to-noise (CNR) of CTA images between these two scanners. CT dose index (CTDI) and dose length product (DLP) for the 256-slice CTA were lower than those for the 64-slice CTA. CONCLUSIONS Low dose CTA of rabbits with 70 or 80 kVp is feasible in a 256-slice or a 64-slice CT scanner. The radiation dose from the 256-slice CTA was much lower than that from the 64-slice CTA with comparable SNR and CNR. The technique can be further applied in longitudinal monitoring of an animal stroke model in the future.
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Affiliation(s)
- Chia-Chi Hsiao
- Department of Radiology, Kaohsiung Veterans General Hospital, Taiwan, R.O.C
| | - Po-Chou Chen
- Department of Biomedical Engineering, I-Shou University, Taiwan, R.O.C
| | - Pei-Chi Kuo
- Department of Biomedical Engineering, I-Shou University, Taiwan, R.O.C
| | - Chih-Hao Ho
- Department of Medical Imaging, Taipei City Hospital (Yangming Branch), Taiwan, R.O.C
| | - Jo-Chi Jao
- Department of Medical Imaging and Radiological Sciences, College of Health Sciences, Kaohsiung Medical University, Taiwan, R.O.C
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Peristaltic Contrast Media Injection Improved Image Quality and Decreased Radiation and Contrast Dose When Compared With Direct Drive Injection During Liver Computed Tomography. J Comput Assist Tomogr 2020; 44:209-216. [DOI: 10.1097/rct.0000000000000994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hou KY, Tsujioka K, Yang CC. Optimization of HU threshold for coronary artery calcium scans reconstructed at 0.5-mm slice thickness using iterative reconstruction. J Appl Clin Med Phys 2020; 21:111-120. [PMID: 31889419 PMCID: PMC7021007 DOI: 10.1002/acm2.12806] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/30/2019] [Accepted: 12/13/2019] [Indexed: 12/22/2022] Open
Abstract
PURPOSE This work investigated the simultaneous influence of tube voltage, tube current, body size, and HU threshold on calcium scoring reconstructed at 0.5-mm slice thickness using iterative reconstruction (IR) through multivariate analysis. Regression results were used to optimize the HU threshold to calibrate the resulting Agatston scores to be consistent with those obtained from the conventional protocol. METHODS A thorax phantom set simulating three different body sizes was used in this study. A total of 14 coronary artery calcium (CAC) protocols were studied, including 1 conventional protocol reconstructed at 3-mm slice thickness, 1 FBP protocol, and 12 statistical IR protocols (3 kVp values*4 SD values) reconstructed at 0.5-mm slice thickness. Three HU thresholds were applied for calcium identification, including 130, 150, and 170 HU. A multiple linear regression method was used to analyze the impact of kVp, SD, body size, and HU threshold on the Agatston scores of three calcification densities for IR-reconstructed CAC scans acquired with 0.5-mm slice thickness. RESULTS Each regression relationship has R2 larger than 0.80, indicating a good fit to the data. Based on the regression models, the HU thresholds as a function of SD estimated to ensure the quantification accuracy of calcium scores for 120-, 100-, and 80-kVp CAC scans reconstructed at 0.5-mm slice thickness using IR for three different body sizes were proposed. Our results indicate that the HU threshold should be adjusted according to the imaging condition, whereas a 130-HU threshold is appropriate for 120-kVp CAC scans acquired with SD = 55 for body size of 24.5 cm. CONCLUSION The optimized HU thresholds were proposed for CAC scans reconstructed at 0.5-mm slice thickness using IR. Our study results may provide a potential strategy to improve the reliability of calcium scoring by reducing partial volume effect while keeping radiation dose as low as reasonably achievable.
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Affiliation(s)
- Kuei-Yuan Hou
- Department of Radiology, Cathay General Hospital, Taipei, Taiwan
| | - Katsumi Tsujioka
- Faculty of Radiological Technology, Fujita Health University, Aichi, Japan
| | - Ching-Ching Yang
- Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan
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Mohammadbeigi A, Khoshgard K, Haghparast A, Eivazi MT. LOCAL DRLS FOR PAEDIATRIC CT EXAMINATIONS BASED ON SIZE-SPECIFIC DOSE ESTIMATES IN KERMANSHAH, IRAN. RADIATION PROTECTION DOSIMETRY 2019; 186:496-506. [PMID: 31330009 DOI: 10.1093/rpd/ncz056] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 03/12/2019] [Accepted: 03/26/2019] [Indexed: 06/10/2023]
Abstract
Due to the radiosensitivity of paediatric patients to X-ray, it is necessary to survey the paediatric DRLs using size-specific dose estimates (SSDE). In the present study, we determined the local diagnostic reference levels (DRLs) for paediatric chest, head and abdomen-pelvis CT examinations and their Surview scans in Kermanshah city, Iran. For ≤1 year, 1-5 years, 5-10 years and 10-15 years the DRLs (mGy) based on SSDE were determined N/A, 6.00, 6.25, 8.27 for abdomen-pelvis, and 8.74, 7.45, 11.15, 10.45 for chest and 19.05, 18.33, 18.22, 20.14 for head examinations, respectively. The differences between body size and default phantom defined in CT scanners are significant and should be considered when determining the DRLs. Based on our findings, use of CTDIv and SSDE parameters for determining DRLs leads to significant different results in children; thus SSDE is suggested as a more accurate index than CTDIV for establishing DRLs in paediatric CT examinations.
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Affiliation(s)
- Ahmad Mohammadbeigi
- M.Sc in Medical Physics, Students Research Committee, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Karim Khoshgard
- Department of Medical Physics, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Abbas Haghparast
- Department of Medical Physics, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mohammad Taghi Eivazi
- Department of Medical Physics, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Georgiev E, Radeva R, Naseva E, Kirova-Nedyalkova G. COMPARISON OF RADIATION DOSE AND IMAGE QUALITY IN CTA OF THE PERIPHERAL ARTERIES. RADIATION PROTECTION DOSIMETRY 2019; 186:437-442. [PMID: 31034552 DOI: 10.1093/rpd/ncz045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 02/25/2019] [Accepted: 03/12/2019] [Indexed: 06/09/2023]
Abstract
The aim of this study is to investigate the possibility of replacing the standard CTA protocol for peripheral arteries with a low dose CTA protocol without affecting the diagnostic image quality. Therefore a single centre retrospective study was conducted involving 200 exams of patients undergoing lower limb angiography. All exams were performed on a 64-row detector CT and the vascular density, muscle density, noise and radiation dose of each image were assessed. The subjective image quality was evaluated additionally by an experienced radiologist. Significant differences were observed in radiation dose and image quality between the standard CTA protocol and the lower dose CTA protocol. No differences were found between objective and subjective image quality. Using 80kVp instead of 120kVp as the tube voltage for lower limb CTA reduces the radiation dose without affecting the diagnostic image quality.
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Affiliation(s)
- Emil Georgiev
- Radiology Department, Acibadem City Clinic Tokuda Hospital, 51B 'Nikola I. Vaptsarov' Blvd., Sofia, Bulgaria
| | - Radina Radeva
- Radiology Department, Acibadem City Clinic Tokuda Hospital, 51B 'Nikola I. Vaptsarov' Blvd., Sofia, Bulgaria
| | - Emilia Naseva
- Radiology Department, Acibadem City Clinic Tokuda Hospital, 51B 'Nikola I. Vaptsarov' Blvd., Sofia, Bulgaria
| | - Galina Kirova-Nedyalkova
- Radiology Department, Acibadem City Clinic Tokuda Hospital, 51B 'Nikola I. Vaptsarov' Blvd., Sofia, Bulgaria
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CT angiography for pulmonary embolism in the emergency department: investigation of a protocol by 20 ml of high-concentration contrast medium. Radiol Med 2019; 125:137-144. [PMID: 31659676 DOI: 10.1007/s11547-019-01098-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 10/15/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVES To retrospectively compare semi-qualitative and quantitative CT pulmonary angiography (CTPAs) image metrics testing diagnostic performance between protocols performed by 20 or 40 ml of contrast medium (CM) in patients with suspected pulmonary embolism (PE). METHODS A total of 102 CTPAs performed by 20 ml (ultra-low volume: ULV) and 74 CTPAs performed by 40 ml (low volume: LV) protocol for the diagnosis of clinically suspected PE performed between October 2012 and September 2013 were retrieved. High-concentration CM (Iomeprol 400 mgI/ml) was injected at 3 ml/s (iodine delivery rate 1.2 mgI/s). Two radiologists (blinded and independent) semi-qualitatively scored vascular enhancement and image noise according to a five-point visual scoring system. Quantitative analysis was performed by regions of interest quantifying densitometric parameters, such as central and peripheral pulmonary arteries vascular contrast enhancement (CE, threshold for diagnostic CE ≥ 250 HU), and metrics for image noise. Continuous variables were compared by the Student's t test between groups if normally distributed while categorical variables were analyzed with the Chi-squared test. Interobserver agreement was calculated by the weighted kappa test; correlation coefficients were calculated using Pearson's correlation tests. RESULTS The semi-qualitative scores for central and peripheral pulmonary arteries vascular CE were sufficient by ULV, yet inferior than LV (p < 0.001). Semi-qualitative image noise was comparable between ULV and LV, and the interobserver agreement was only fair for quality of peripheral vessels. Agreement on nondiagnostic semi-qualitative parameters was seen in 9/102 (8.8%) ULV CTPAs, in particular associated with massive PE (2/9), pleuro-pulmonary abnormalities (5/9) or without major abnormalities (2/9). Quantitative analysis showed that mean CE was lower in ULV group (p < 0.001), though greater than the diagnostic threshold of 250 HU in both groups. CONCLUSIONS Diagnostic vascular CE (> 250 HU) was obtained in both 20 ml and 40 ml CTPAs. CTPA by 20 ml of CM rendered diagnostic CE for the assessment of pulmonary arteries in patients with clinical suspicion of acute PE. Decreased image quality was mostly associated with massive PE or concomitant pleuro-parenchymal abnormalities.
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Mousavi Gazafroudi SS, Tavakkoli MB, Moradi M, Mousavi Gazafroudi SS, Yadegarfar G, Behjati M, Karimian M, Sajjadieh Khajouei A. Coronary CT angiography by modifying tube voltage and contrast medium concentration: Evaluation of image quality and radiation dose. Echocardiography 2019; 36:1391-1396. [PMID: 31215700 DOI: 10.1111/echo.14410] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/22/2019] [Accepted: 05/26/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Currently, there is an increasing interest in noninvasive imaging of cardiovascular system such as computed tomography coronary angiography (CCTA). The risks of radiation-induced cancer and contrast-induced nephropathy (CIN) have always been regarded as concerns which increased demand for CCTA using reduced radiation dose and iodine intake. We aimed to evaluate the image quality and radiation dose of CCTA by modifying tube voltage and concentration of contrast media. METHODS The present study includes 105 patients who underwent CCTA for clinical indications. Specific inclusion and exclusion criteria in terms of patient's weight, body mass index, calcium score, and stenting were used. First group of patients scanned by 120 kV and 370 mg I/mL contrast medium, compared with second and third groups for which scanning was performed using 100 kV and 370 mg I/mL and 100 kV and 300 mg I/mL, respectively. Image quality was evaluated both subjectively and objectively. The effective dose and iodine intake were also measured. RESULTS Using low kV protocols led to radiation dose reduction up to 38% and applying low contrast medium concentration with consequent reduced iodine intake up to 21%. Moreover, there were significant differences in image quality of new scanning protocols. CONCLUSION Reduction in tube voltage with lowering of contrast medium concentration can reduce radiation dose and iodine intake with acceptable image quality.
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Affiliation(s)
| | | | - Maryam Moradi
- Radiology Department, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Ghasem Yadegarfar
- Epidemiology Department, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohaddeseh Behjati
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Karimian
- Anatomical Sciences Research Center, Kashan University of Medical Sciences, Kashan, Iran
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Tan SK, Ng KH, Yeong CH, Raja Aman RRA, Mohamed Sani F, Abdul Aziz YF, Sun Z. Personalized administration of contrast medium with high delivery rate in low tube voltage coronary computed tomography angiography. Quant Imaging Med Surg 2019; 9:552-564. [PMID: 31143647 DOI: 10.21037/qims.2019.03.13] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Background High delivery rate is an important factor in optimizing contrast medium administration in coronary computed tomography angiography (CCTA). A personalized contrast volume calculation algorithm incorporating high iodine delivery rate (IDR) can reduce total iodine dose (TID) and produce optimal vessel contrast enhancement (VCE) in low tube voltage CCTA. In this study, we developed and validated an algorithm for calculating the volume of contrast medium delivered at a high rate for patients undergoing retrospectively ECG-gated CCTA with low tube voltage protocol. Methods The algorithm for an IDR of 2.22 gI·s-1 was developed based on the relationship between VCE and contrast volume in 141 patients; test bolus parameters and characteristics in 75 patients; and, tube voltage in a phantom study. The algorithm was retrospectively tested in 45 patients who underwent retrospectively ECG-gated CCTA with a 100 kVp protocol. Image quality, TID and radiation dose exposure were compared with those produced using the 120 kVp and routine contrast protocols. Results Age, sex, body surface area (BSA) and peak contrast enhancement (PCE) were significant predictors for VCE (P<0.05). A strong linear correlation was observed between VCE and contrast volume (r=0.97, P<0.05). The 100-to-120 kVp contrast enhancement conversion factor (Ec) was calculated at 0.81. Optimal VCE (250 to 450 HU) and diagnostic image quality were obtained with significant reductions in TID (32.1%) and radiation dose (38.5%) when using 100 kVp and personalized contrast volume calculation algorithm compared with 120 kVp and routine contrast protocols (P<0.05). Conclusions The proposed algorithm could significantly reduce TID and radiation exposure while maintaining optimal VCE and image quality in CCTA with 100 kVp protocol.
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Affiliation(s)
- Sock Keow Tan
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kwan Hoong Ng
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Chai Hong Yeong
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | - Raja Rizal Azman Raja Aman
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Fadhli Mohamed Sani
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yang Faridah Abdul Aziz
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Zhonghua Sun
- Discipline of Medical Radiation Sciences, Curtin University, Perth, Australia
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Higaki T, Nakamura Y, Fukumoto W, Honda Y, Tatsugami F, Awai K. Clinical application of radiation dose reduction at abdominal CT. Eur J Radiol 2019; 111:68-75. [DOI: 10.1016/j.ejrad.2018.12.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/08/2018] [Accepted: 12/17/2018] [Indexed: 02/07/2023]
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Clinical application of radiation dose reduction for head and neck CT. Eur J Radiol 2018; 107:209-215. [DOI: 10.1016/j.ejrad.2018.08.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/14/2018] [Accepted: 08/23/2018] [Indexed: 12/12/2022]
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Kanal KM. Invited Commentary on “Radiation Dose Reduction in Pediatric CT,” with Response from Dr Nagayama et al. Radiographics 2018; 38:1440-1442. [DOI: 10.1148/rg.2018180193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Kalpana M. Kanal
- Department of Radiology, University of Washington Seattle, Washington
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Froelich MF, Heinemann V, Sommer WH, Holch JW, Schoeppe F, Hesse N, Baumann AB, Kunz WG, Reiser MF, Ricke J, D’Anastasi M, Stintzing S, Modest DP, Kazmierczak PM, Hofmann FO. CT attenuation of liver metastases before targeted therapy is a prognostic factor of overall survival in colorectal cancer patients. Results from the randomised, open-label FIRE-3/AIO KRK0306 trial. Eur Radiol 2018; 28:5284-5292. [DOI: 10.1007/s00330-018-5454-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 03/26/2018] [Accepted: 03/27/2018] [Indexed: 02/01/2023]
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Tan SK, Yeong CH, Raja Aman RRA, Ng KH, Abdul Aziz YF, Chee KH, Sun Z. Low tube voltage prospectively ECG-triggered coronary CT angiography: a systematic review of image quality and radiation dose. Br J Radiol 2018; 91:20170874. [PMID: 29493261 DOI: 10.1259/bjr.20170874] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE This study aimed (1) to perform a systematic review on scanning parameters and contrast medium (CM) reduction methods used in prospectively electrocardiography (ECG-triggered low tube voltage coronary CT angiography (CCTA), (2) to compare the achievable dose reduction and image quality and (3) to propose appropriate scanning techniques and CM administration methods. METHODS A systematic search was performed in PubMed, the Cochrane library, CINAHL, Web of Science, ScienceDirect and Scopus, where 20 studies were selected for analysis of scanning parameters and CM reduction methods. RESULTS The mean effective dose (HE) ranged from 0.31 to 2.75 mSv at 80 kVp, 0.69 to 6.29 mSv at 100 kVp and 1.53 to 10.7 mSv at 120 kVp. Radiation dose reductions of 38 to 83% at 80 kVp and 3 to 80% at 100 kVp could be achieved with preserved image quality. Similar vessel contrast enhancement to 120 kVp could be obtained by applying iodine delivery rate (IDR) of 1.35 to 1.45 g s-1 with total iodine dose (TID) of between 10.9 and 16.2 g at 80 kVp and IDR of 1.08 to 1.70 g s-1 with TID of between 18.9 and 20.9 g at 100 kVp. CONCLUSION This systematic review found that radiation doses could be reduced to a rate of 38 to 83% at 80 kVp, and 3 to 80% at 100 kVp without compromising the image quality. Advances in knowledge: The suggested appropriate scanning parameters and CM reduction methods can be used to help users in achieving diagnostic image quality with reduced radiation dose.
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Affiliation(s)
- Sock Keow Tan
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Chai Hong Yeong
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | | | - Kwan Hoong Ng
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Yang Faridah Abdul Aziz
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Kok Han Chee
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia.,2 Department of Medicine, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Zhonghua Sun
- 3 Department of Medical Radiation Sciences, Curtin University , Perth, WA , Australia
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