The aim of this study was to compare dose and image quality (IQ) of a baseline low-dose computed tomography (CT) (fix mAs) vs. an ultra-low-dose CT (automatic tube current modulation, ATCM) in patients with suspected urinary stone disease and to assess the added value of iterative reconstruction. CT examination was performed on 193 patients (103 baseline low-dose, 90 ultra-low-dose). Filtered back projection (FBP) was used for both protocols, and Sinogram Affirmed Iterative Reconstruction (SAFIRE) was used for the ultra-low-dose protocol only. Dose and ureter stones information were collected for both protocols. Subjective IQ was assessed by two radiologists scoring noise, visibility of the ureter and overall IQ. Objective IQ (contrast-to-noise ratio, CNR) was assessed for the ultra-low-dose protocol only (FBP and SAFIRE). The ultra-low-dose protocol (ATCM) showed a 22% decrease in mean effective dose (p < 0.001) and improved visibility of the pelvic ureter (p = 0.02). CNR was higher for SAFIRE (p < 0.0001). SAFIRE improves the objective IQ, but not the subjective IQ for the chosen clinical task.
Radiation protection dosimetry. 2016 May 31 [Epub ahead of print]
Olivier Soenen, Christophe Balliauw, Raymond Oyen, Federica Zanca
Department of Radiology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium ., Department of Radiology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium., Department of Radiology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium Department of imaging and Pathology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium., Department of Radiology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium Department of imaging and Pathology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium.