RATIONALE AND OBJECTIVES: This study aims to estimate observer performance for a range of dose levels for common computed tomography (CT) examinations (detection of liver metastases or pulmonary nodules, and cause of neurologic deficit) to prioritize noninferior dose levels for further analysis. MATERIALS AND METHODS: Using CT data from 131 examinations (abdominal CT, 44; chest CT, 44; head CT, 43), CT images corresponding to 4%-100% of the routine clinical dose were reconstructed with filtered back projection or iterative reconstruction. Radiologists evaluated CT images, marking specified targets, providing confidence scores, and grading image quality. Noninferiority was assessed using reference standards, reader agreement rules, and jackknife alternative free-response receiver operating characteristic figures of merit. Reader agreement required that a majority of readers at lower dose identify target lesions seen by the majority of readers at routine dose. RESULTS: Reader agreement identified dose levels lower than 50% and 4% to have inadequate performance for detection of hepatic metastases and pulmonary nodules, respectively, but could not exclude any low dose levels for head CT. Estimated differences in jackknife alternative free-response receiver operating characteristic figures of merit between routine and lower dose configurations found that only the lowest dose configurations tested (ie, 30%, 4%, and 10% of routine dose levels for abdominal, chest, and head CT examinations, respectively) did not meet criteria for noninferiority. At lower doses, subjective image quality declined before observer performance. Iterative reconstruction was only beneficial when filtered back projection did not result in noninferior performance. CONCLUSION: Opportunity exists for substantial radiation dose reduction using existing CT technology for common diagnostic tasks.
RATIONALE AND OBJECTIVES: This study aims to estimate observer performance for a range of dose levels for common computed tomography (CT) examinations (detection of liver metastases or pulmonary nodules, and cause of neurologic deficit) to prioritize noninferior dose levels for further analysis. MATERIALS AND METHODS: Using CT data from 131 examinations (abdominal CT, 44; chest CT, 44; head CT, 43), CT images corresponding to 4%-100% of the routine clinical dose were reconstructed with filtered back projection or iterative reconstruction. Radiologists evaluated CT images, marking specified targets, providing confidence scores, and grading image quality. Noninferiority was assessed using reference standards, reader agreement rules, and jackknife alternative free-response receiver operating characteristic figures of merit. Reader agreement required that a majority of readers at lower dose identify target lesions seen by the majority of readers at routine dose. RESULTS: Reader agreement identified dose levels lower than 50% and 4% to have inadequate performance for detection of hepatic metastases and pulmonary nodules, respectively, but could not exclude any low dose levels for head CT. Estimated differences in jackknife alternative free-response receiver operating characteristic figures of merit between routine and lower dose configurations found that only the lowest dose configurations tested (ie, 30%, 4%, and 10% of routine dose levels for abdominal, chest, and head CT examinations, respectively) did not meet criteria for noninferiority. At lower doses, subjective image quality declined before observer performance. Iterative reconstruction was only beneficial when filtered back projection did not result in noninferior performance. CONCLUSION: Opportunity exists for substantial radiation dose reduction using existing CT technology for common diagnostic tasks.
Authors: J G Fletcher; D R DeLone; A L Kotsenas; N G Campeau; V T Lehman; L Yu; S Leng; D R Holmes; P K Edwards; M P Johnson; G J Michalak; R E Carter; C H McCollough Journal: AJNR Am J Neuroradiol Date: 2019-10-24 Impact factor: 3.825
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Authors: Parvathy Sudhir Pillai; Scott Hsieh; David Holmes; Rickey Carter; Joel G Fletcher; Cynthia McCollough Journal: Proc SPIE Int Soc Opt Eng Date: 2022-04-04
Authors: Scott S Hsieh; Akitoshi Inoue; Parvathy Sudhir Pillai; Hao Gong; David R Holmes; David A Cook; Shuai Leng; Lifeng Yu; Rickey E Carter; Joel G Fletcher; Cynthia H McCollough Journal: Proc SPIE Int Soc Opt Eng Date: 2022-04-04
Authors: Hao Gong; Joel G Fletcher; Jay P Heiken; Michael L Wells; Shuai Leng; Cynthia H McCollough; Lifeng Yu Journal: Med Phys Date: 2021-12-01 Impact factor: 4.506
Authors: Joel G Fletcher; Jeff L Fidler; Sudhakar K Venkatesh; David M Hough; Naoki Takahashi; Lifeng Yu; Matthew Johnson; Shuai Leng; David R Holmes; Rickey Carter; Cynthia H McCollough Journal: Radiology Date: 2018-09-11 Impact factor: 11.105
Authors: Joel G Fletcher; David L Levin; Anne-Marie G Sykes; Rebecca M Lindell; Darin B White; Ronald S Kuzo; Vighnesh Suresh; Lifeng Yu; Shuai Leng; David R Holmes; Akitoshi Inoue; Matthew P Johnson; Rickey E Carter; Cynthia H McCollough Journal: Radiology Date: 2020-09-29 Impact factor: 11.105
Authors: Taylor R Moen; Baiyu Chen; David R Holmes; Xinhui Duan; Zhicong Yu; Lifeng Yu; Shuai Leng; Joel G Fletcher; Cynthia H McCollough Journal: Med Phys Date: 2020-12-16 Impact factor: 4.071