Subjective image assessment was performed by four radiologists with an average of 2 years of experience (ranging from 1 to 4 years). For each protocol and patient, the full batch of images (on average 1001 slices) is presented in axial and coronal orientation. In total 66 (11 patients, 3 reconstruction algorithms, and 2 view planes) full batches of images are evaluated in random order. Each radiologist individually performed the assessment by ranking one after the other dataset on a diagnostic workstation. Due to the increased iodine contrast, a CTA window setting of center: 200 HU and width: 1200 HU was chosen for diagnostic evaluation. The radiologists did have experience with commercially available iterative reconstruction algorithms, but they did not have previous experience with IMBR reconstructed data. Before starting the rating of the images, the different quality metrics were discussed with each radiologist. This step was done to insure a common understanding for the different metrics. All four radiologists independently rated the following image quality metrics. Images were addressed for subjective image noise on a 4-point scale (1 = minimal image noise, 2 = less than average noise, 3 = above average noise, 4 = unacceptable image noise); image artifacts on a 4-point scale (1 = no artifacts, 2 = minor artifacts not interfering with diagnostic decision making, 3 = major artifacts affecting visualization of major structures but diagnosis still possible, 4 = artifacts affecting diagnostic information); diagnostic confidence on a 4-point scale (1 = completely confident, 2 = probably confident, 3 = confident only for a limited clinical entity, 4 = poor confidence); image impression on a 4-point scale (1 = natural, 2 = limited natural, 3 = limited artificial, 4 = artificial); and with respect to vascular detectability of third-order and higher aortic branches on a 4-point scale (1 = detectable, 2 = probably detectable, 3 = limited detectability, 4 = poor detectability). Kappa values were calculated to compare interobserver agreement on a per-patient basis for all image quality metrics.