Impact of contrast injection and stent-graft implantation on reproducibility of volume measurements in semiautomated segmentation of abdominal aortic aneurysm on computed tomography

Abstract

Purpose To assessthe impact of contrast injection and stent-graft implantation on feasibility, accuracy, and reproducibilityof abdominal aortic aneurysm (AAA) volume and maximaldiameter (D-max) measurements using segmentation software. Materials and methods CT images of 80 subjects presentingAAA were divided into four equal groups: with or without contrast enhancement, and with or without stent-graft implantation. Semiautomated software was used to segment the aortic wall, once by an expert and twice by three readers. Volume and D-max reproducibility was estimated by intraclass correlation coefficients (ICC), and accuracy was estimated between the expert and the readers by mean relative errors. Results All segmentations were technically successful. Themean AAA volume was 167.0±82.8 mL and the mean D-max 55.0±10.6 mm. Inter- and intraobserver ICCs for volume andD-max measurements were greater than 0.99. Mean relative errors between readers varied between −1.8±4.6 and 0.0± 3.6 mL. Mean relative errors in volume and D-max measurements between readers showed no significant difference between the four groups (P≥0.2). Conclusion The feasibility, accuracy, and reproducibility of AAA volume and D-max measurements using segmentation software were not affected by the absence of contrast injection or the presence of stent-graft.