MRI Measurements of Wall Shear Stress in the Descending Aorta Downstream of an Ascending Aortic Aneurysm

Andrew L. Wentland^1,2, Erik T. Bieging², Alex Frydrychowicz², Thomas M. Grist^1,2, Oliver Wieben¹, Chris J. Francois²

While studies have shown that high wall shear stress (WSS) creates aneurysms and low WSS contributes to aneurysmal growth, the downstream effects of an aneurysm on WSS remain unknown. In this study we compared measurements of peak WSS in the descending aorta of volunteers and in patients with an ascending aortic aneurysm. Measurements of peak WSS were lower in patients than in normal volunteers; the percent increase in WSS from diastolic baseline to peak systole was greater in volunteers than in patients. The long-term effects of lower WSS in the patients require further investigation.