Taylor B Smith1,2,3, Shuaiqi Zhang4, Alaattin Erkanli4, Donald Frush5, Ehsan Samei1,2,3. 1. Duke University, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Durham, North Carolina, United States. 2. Duke University, Medical Physics Graduate Program, Durham, North Carolina, United States. 3. Duke University Medical Center, Durham, North Carolina, United States. 4. Duke University School of Medicine, BERD Methods Core, Department of Biostatistics and Bioinformatics, Durham, North Carolina, United States. 5. Stanford University, Lucile Salter Packard Children's Hospital, Stanford, California, United States.
Abstract
Purpose: To characterize variability in image quality and radiation dose across a large cohort of computed tomography (CT) examinations and identify the scan factors with the highest influence on the observed variabilities. Approach: This retrospective institutional-review-board-exempt investigation was performed on 87,629 chest and abdomen-pelvis CT scans acquired for 97 facilities from 2018 to 2019. Images were assessed in terms of noise, resolution, and dose metrics (global noise, frequency in which modulation transfer function is at 0.50, and volumetric CT dose index, respectively). The results were fit to linear mixed-effects models to quantify the variabilities as affected by scan parameters and settings and patient characteristics. A list of factors, ranked by t -value with p < 0.05 , was ascertained for each of the six mixed effects models. A type III p -value test was used to assess the influence of facility. Results: Across different facilities, image quality and dose were significantly different ( p < 0.05 ), with little correlation between their mean magnitudes and consistency (Pearson's correlation coefficient < 0.34 ). Scanner model, slice thickness, recon field-of-view and kernel, mAs, kVp, patient size, and centering were the most influential factors. The two body regions exhibited similar rankings of these factors for noise (Spearman's correlation coefficient = 0.76 ) and dose (Spearman's correlation coefficient = 0.86 ) but not for resolution (Spearman's correlation coefficient = 0.52 ). Conclusions: Clinical CT scans can vary in image quality and dose with broad implications for diagnostic utility and radiation burden. Average scan quality was not correlated with interpatient scan-quality consistency. For a given facility, this variability can be quite large, with magnitude differences across facilities. The knowledge of the most influential factors per body region may be used to better manage these variabilities within and across facilities.
Purpose: To characterize variability in image quality and radiation dose across a large cohort of computed tomography (CT) examinations and identify the scan factors with the highest influence on the observed variabilities. Approach: This retrospective institutional-review-board-exempt investigation was performed on 87,629 chest and abdomen-pelvis CT scans acquired for 97 facilities from 2018 to 2019. Images were assessed in terms of noise, resolution, and dose metrics (global noise, frequency in which modulation transfer function is at 0.50, and volumetric CT dose index, respectively). The results were fit to linear mixed-effects models to quantify the variabilities as affected by scan parameters and settings and patient characteristics. A list of factors, ranked by t -value with p < 0.05 , was ascertained for each of the six mixed effects models. A type III p -value test was used to assess the influence of facility. Results: Across different facilities, image quality and dose were significantly different ( p < 0.05 ), with little correlation between their mean magnitudes and consistency (Pearson's correlation coefficient < 0.34 ). Scanner model, slice thickness, recon field-of-view and kernel, mAs, kVp, patient size, and centering were the most influential factors. The two body regions exhibited similar rankings of these factors for noise (Spearman's correlation coefficient = 0.76 ) and dose (Spearman's correlation coefficient = 0.86 ) but not for resolution (Spearman's correlation coefficient = 0.52 ). Conclusions: Clinical CT scans can vary in image quality and dose with broad implications for diagnostic utility and radiation burden. Average scan quality was not correlated with interpatient scan-quality consistency. For a given facility, this variability can be quite large, with magnitude differences across facilities. The knowledge of the most influential factors per body region may be used to better manage these variabilities within and across facilities.
Authors: Kalpana M Kanal; Janessa M Graves; Monica S Vavilala; Kimberly E Applegate; Jeffrey G Jarvik; Frederick P Rivara Journal: AJR Am J Roentgenol Date: 2015-03 Impact factor: 3.959
Authors: Francesco Ria; Joseph T Davis; Justin B Solomon; Joshua M Wilson; Taylor B Smith; Donald P Frush; Ehsan Samei Journal: AJR Am J Roentgenol Date: 2019-06-10 Impact factor: 3.959
Authors: Mary A King; Kalpana M Kanal; Annemarie Relyea-Chew; Mark Bittles; Monica S Vavilala; William Hollingworth Journal: Pediatr Radiol Date: 2009-06-25
Authors: Pauli Virtanen; Ralf Gommers; Travis E Oliphant; Matt Haberland; Tyler Reddy; David Cournapeau; Evgeni Burovski; Pearu Peterson; Warren Weckesser; Jonathan Bright; Stéfan J van der Walt; Matthew Brett; Joshua Wilson; K Jarrod Millman; Nikolay Mayorov; Andrew R J Nelson; Eric Jones; Robert Kern; Eric Larson; C J Carey; İlhan Polat; Yu Feng; Eric W Moore; Jake VanderPlas; Denis Laxalde; Josef Perktold; Robert Cimrman; Ian Henriksen; E A Quintero; Charles R Harris; Anne M Archibald; Antônio H Ribeiro; Fabian Pedregosa; Paul van Mulbregt Journal: Nat Methods Date: 2020-02-03 Impact factor: 28.547