caa a22 4500 605493294 CHVBK 20210128100520.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s00261-015-0411-2 doi (NATIONALLICENCE)springer-10.1007/s00261-015-0411-2 CT for evaluation of urolithiasis: image quality of ultralow-dose (Sub mSv) CT with knowledge-based iterative reconstruction and diagnostic performance of low-dose CT with statistical iterative reconstruction [Elektronische Daten] [Joonho Hur, Sung Park, Jong Lee, Hyun Park, In Chang, Jong Kwon, Yang Kim] Purpose: To compare radiation dose and image quality in regular, low, and ultralow-dose CT protocols, and to evaluate diagnostic performance of low-dose CT for urolithiasis. Materials and methods: Sixty-five patients with suspected urolithiasis underwent three different scans under the regular, low, and ultralow-dose protocols. The regular dose scans were reconstructed using filtered back projection and the low-dose scans were reconstructed using a statistical iterative reconstruction. The ultralow-dose scans were reconstructed using both techniques in addition to a knowledge-based IR. Effective radiation doses were compared. Objective image noise was assessed by measuring standard deviation of HU and subjective image assessment was performed with a 3- or 5-point scale. Diagnostic performance of the low-dose image was evaluated, using the regular dose image as a standard reference and the interobserver agreement between two reviewers with different levels of experience was calculated. Results: The effective radiation dose was significantly different in each protocol (p<0.001) and estimated dose reduction of the low-dose and ultralow-dose protocols was 76.4% and 89.8%, respectively. The knowledge-based iterative reconstruction algorithm showed poorer subjective image quality than the regular and low-dose protocols, but it also had the least objective image noise. Overall, the low-dose image set showed a greater than 84% concordance rate and 100% in ureter stones larger than 3mm. Interobserver agreement was substantial (kappa value=0.61). Conclusions: The knowledge-based IR can provide a better quality image while reducing radiation exposure under the same protocol. Furthermore, the diagnostic performance of the low-dose CT protocol is comparable to the regular dose scan. Springer Science+Business Media New York, 2015 Knowledge-based iterative reconstruction nationallicence Model-based iterative reconstruction nationallicence Statistical iterative reconstruction nationallicence Filtered back projection nationallicence Urolithiasis nationallicence Low-dose computed tomography nationallicence Radiation dosage nationallicence Hur Joonho Department of Radiology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Park Sung Department of Radiology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Lee Jong Department of Radiology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Park Hyun Department of Radiology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Chang In Department of Urology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Kwon Jong Department of Urology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Kim Yang Department of Radiology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut Abdominal Imaging Springer US; http://www.springer-ny.com 40/7(2015-10-01), 2432-2440 0942-8925 40:7<2432 2015 40 261 https://doi.org/10.1007/s00261-015-0411-2 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/s00261-015-0411-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hur Joonho Department of Radiology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 700 1- Park Sung Department of Radiology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 700 1- Lee Jong Department of Radiology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 700 1- Park Hyun Department of Radiology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 700 1- Chang In Department of Urology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 700 1- Kwon Jong Department of Urology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 700 1- Kim Yang Department of Radiology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, 102, Heukseok-ro, Dongjak-gu, 156-755, Seoul, Korea aut NATIONALLICENCE 773 0- Abdominal Imaging Springer US; http://www.springer-ny.com 40/7(2015-10-01), 2432-2440 0942-8925 40:7<2432 2015 40 261