Reproducibility of wall shear stress in abdominal aortic aneurysms estimated by 4D flow magnetic resonance imaging

The aim of this study was to assess the reproducibility and inter- and intra-observer agreement for estimating wall shear stress (WSS) in abdominal aortic aneurysms (AAAs) based on 4D flow magnetic resonance imaging (MRI). Asymptomatic AAA patients were included and scanned twice with a one-week interval. Phase-contrast angiographies were acquired by voxel-wise multiplication of magnitude and phase data. Based on statistical analyses the reproducibility was good. An inverse correlation was found between WSS and lumen diameter. Both vorticity and intraluminal thrombus volume were associated with minimum WSS in AAA. 4D flow MRI is robust for estimating WSS in AAAs.