Automatic accurate non-invasive quantitation of blood flow, cross-sectional vessel area, and wall shear stress by modelling of magnetic resonance velocity data

Objectives: to apply a new, automatic and non-invasive method for quantification of blood flow, dynamic mass-sectional vessel area, and wall shear stress (WSS) by in vivo magnetic resonance velocity mapping of normal subjects. Design: prospective, open study. Materials: six young volunteers. Methods: a three-dimensional paraboloid model enabling automatic determination of bloodflow, vessel distensibility and WSS was applied to blood velocity determinations in the common carotid artery. Blood flow was also determined by a manual edge detection method. Results: using the new method, the common carotid mean blood flow was 7.28 (5.61-9.63) (mean (range)) ml/s. By;the manual method blood flow was 7.21 (5.55-9.60) ml/s. Mean luminal vessel area was 26% larger in peak systole than in diastole. Mean/peak WSS was 0.82/2.28 N/m(2). Manually and automatically determined flows correlated (r(2) = 0.998, p < 0.0001). WSS and peak centre velocity were associated (r(2) = 0.805, p < 0.0001). Conclusions: bloodflow, luminal vessel area dilatation, and WSS can be determined by the automatic three-dimensional paraboloid method. The hypothesis of association between peak centre velocity and WSS was not contradicted by the results of the present study.