caa a22 4500 605494460 CHVBK 20210128100526.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s00261-015-0504-y doi (NATIONALLICENCE)springer-10.1007/s00261-015-0504-y Knowledge-based iterative model reconstruction (IMR) algorithm in ultralow-dose CT for evaluation of urolithiasis: evaluation of radiation dose reduction, image quality, and diagnostic performance [Elektronische Daten] [Sung Park, Yang Kim, Jong Lee, Hyun Park] Purpose: To evaluate the efficacy of a knowledge-based iterative model reconstruction (IMR) algorithm for reducing image noise in ultralow-dose (ULD) CT for urolithiasis. Materials and methods: A total of 103 patients diagnosed withurinary stones (n=276) were enrolled. Regular dose (RD) scans (120kV and 150mAs, maximal tube current in dose modulation) were reconstructed using filtered back-projection (FBP, RD-FBP), and ULD scans (100kV and 20mAs, fixed tube current) were reconstructed with FBP (ULD-FBP), statistical iterative reconstruction (IR; ULD-iDose), and a knowledge-based IMR algorithm (ULD-IMR). Prospective interpretations of the two scans wereperformed with respect to radiation dose, objective image noise, and subjective assessment. The subjective assessment was also evaluated with regard to each patient's body mass index (BMI,<25 or≥25kg/m2). Using RD CT (RD-FBP) as the reference standard, two reviewers assessed the diagnostic performance and inter-observeragreement for ULD-IMR. Result: The average effective doses with RD CT and ULD CT were 8.31 and 0.68mSv,respectively, and the average radiation dose reduction rate was 91.82% (p<0.01). The lowest objective image noise was observed with ULD-IMR (p<0.01). Subjective assessment in ULD-IMR was comparable to that of RD-FBP, although RD-FBP remained statistically superior. For BMI, there was a statistically significant difference in subjective image quality between the normal (4.7±0.54) and overweight or obese groups (4.2±0.5) (p<0.05). The ULD-IMR showed a greater than 75% concordant rate in overall stones and 100% in ureter stones larger than 3mm. However, for stones<3mm, neither reviewer had a good detection rate (45.5% and 56.9% for the general and genitourinary radiologist, respectively). Inter-observer agreement was almost perfect (κ=0.82). Conclusion: Despite a significant radiation dose reduction, ULD-IMR images were comparable in image quality and noise to RD-FBP images. Furthermore, the diagnostic performance of the ULD non-enhanced CT protocol was comparable to that of the RD scan for diagnosing urinary stones larger than 3mm. Springer Science+Business Media New York, 2015 Knowledge-based iterative model reconstruction nationallicence Model-based iterative reconstruction nationallicence Statistical iterative reconstruction nationallicence Urolithiasis nationallicence Low-dose computed tomography nationallicence Park Sung Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Kim Yang Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Lee Jong Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Park Hyun Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Abdominal Imaging Springer US; http://www.springer-ny.com 40/8(2015-10-01), 3137-3146 0942-8925 40:8<3137 2015 40 261 https://doi.org/10.1007/s00261-015-0504-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00261-015-0504-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Park Sung Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 700 1- Kim Yang Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 700 1- Lee Jong Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 700 1- Park Hyun Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 773 0- Abdominal Imaging Springer US; http://www.springer-ny.com 40/8(2015-10-01), 3137-3146 0942-8925 40:8<3137 2015 40 261