Elena Tonkopi1,2, Susan Duffy1,2, Mohamed Abdolell1,2, Daria Manos1,2. 1. 1 Department of Diagnostic Radiology, Dalhousie University, 1276 South Park St, PO Box 9000, Halifax, NS B3H 2Y9, Canada. 2. 2 Department of Diagnostic Imaging, Nova Scotia Health Authority, Halifax, NS, Canada.
Abstract
OBJECTIVE: The purpose of this study is to establish provincial diagnostic reference levels (DRLs) and to determine whether this process may help reduce the patient radiation dose from the most frequently performed CT examinations. MATERIALS AND METHODS: We investigated the following CT examinations: head, chest, low-dose chest, abdomen and pelvis, and chest, abdomen, and pelvis examinations. The sample for each protocol included 15 patients of average body weight (mean [± SD], 70 ± 20 kg). The differences in dose between scanners were evaluated using one-way ANOVA. Correlations between dose, scanner age, and the number of detector rows were assessed using the Pearson correlation coefficient. A sample of abdominal and chest examinations were randomized and blinded for review by experienced radiologists who graded diagnostic image quality. Provincial DRLs were calculated as the 75th percentile of patient dose distributions. For hospitals with doses exceeding the DRLs, dose reduction was recommended, followed by another survey. RESULTS: The initial survey included data of 1185 patients, and an additional 180 patients were surveyed after protocol optimization. The differences between the mean values of the dose distributions from each scanner were statistically significant (p < 0.05) for all examinations. The variation was greatest for low-dose chest CT, with a greater than fivefold difference in the mean dose values noted between scanners. A very weak correlation was found between dose and scanner age or the number of detector rows. Analysis of image quality revealed no statistically significant differences in any scoring categories, with the exception of the noise category in abdominal imaging. Implementation of the DRLs allowed a reduction in patient dose of up to 41% as a result of a protocol change. CONCLUSION: Establishing provincial DRLs allows an effective reduction in patient dose without resulting in degradation of image quality.
OBJECTIVE: The purpose of this study is to establish provincial diagnostic reference levels (DRLs) and to determine whether this process may help reduce the patient radiation dose from the most frequently performed CT examinations. MATERIALS AND METHODS: We investigated the following CT examinations: head, chest, low-dose chest, abdomen and pelvis, and chest, abdomen, and pelvis examinations. The sample for each protocol included 15 patients of average body weight (mean [± SD], 70 ± 20 kg). The differences in dose between scanners were evaluated using one-way ANOVA. Correlations between dose, scanner age, and the number of detector rows were assessed using the Pearson correlation coefficient. A sample of abdominal and chest examinations were randomized and blinded for review by experienced radiologists who graded diagnostic image quality. Provincial DRLs were calculated as the 75th percentile of patient dose distributions. For hospitals with doses exceeding the DRLs, dose reduction was recommended, followed by another survey. RESULTS: The initial survey included data of 1185 patients, and an additional 180 patients were surveyed after protocol optimization. The differences between the mean values of the dose distributions from each scanner were statistically significant (p < 0.05) for all examinations. The variation was greatest for low-dose chest CT, with a greater than fivefold difference in the mean dose values noted between scanners. A very weak correlation was found between dose and scanner age or the number of detector rows. Analysis of image quality revealed no statistically significant differences in any scoring categories, with the exception of the noise category in abdominal imaging. Implementation of the DRLs allowed a reduction in patient dose of up to 41% as a result of a protocol change. CONCLUSION: Establishing provincial DRLs allows an effective reduction in patient dose without resulting in degradation of image quality.
Authors: Yiming Gao; Usman Mahmood; Tianyu Liu; Brian Quinn; Marc J Gollub; X George Xu; Lawrence T Dauer Journal: AJR Am J Roentgenol Date: 2019-08-15 Impact factor: 3.959
Authors: Yiming Gao; Brian Quinn; Neeta Pandit-Taskar; Gerald Behr; Usman Mahmood; Daniel Long; X George Xu; Jean St Germain; Lawrence T Dauer Journal: Phys Med Date: 2017-12-22 Impact factor: 2.685
Authors: Elena Tonkopi; Eline Jahre Wikan; Tor Olav Hovland; Sivert Høgset; Thomas Alexander Kofod; Selasi K Sefenu; Emily Hughes-Ryan; Dakota D Entremont-O Connell; Catherine Gunn; Tanja Holter; Safora Johansen Journal: Acta Radiol Open Date: 2022-10-07