Evaluation of aortic regurgitation by cardiac cine magnetic resonance imaging: planar analysis and comparison to Doppler echocardiography.

Abstract

Cine magnetic resonance imaging (MRI) displays cardiac flow in cine loop fashion on multiple tomographic sections. Since laminar flow is easily distinguished from turbulent flow, cine MRI may be uniquely suited to the study of valvular regurgitation: the entire cardiac volume can be sampled and the regurgitant jet at the valve plane can be depicted. We therefore assessed aortic regurgitation (AR) by cine MRI in 35 patients and 11 normal volunteers and compared results to pulsed (n = 32) or color flow Doppler (n = 14). The extent of the flow disturbance was estimated for both cine MRI and Doppler by indexing the size of the maximal, single plane regurgitant jet area (JA) to the left ventricular (LV) area. Cine MRI JA/LV ratio compared well with pulsed (r = 0.81) and color flow (r = 0.88) Doppler; classification as mild (less than 20%), moderate (20-40%), and severe (greater than 40%) AR by both methods was identical in 43 of 46 cases with no differences of more than one grade. Overall sensitivity and specificity of cine MRI, compared to Doppler, were 94 and 95%, respectively. Cine MRI also depicted the regurgitant jet at the valve plane in 11 patients. Thus planar analysis of cine MRI images in patients with AR provides a semiquantitative assessment of the AR flow disturbance which is similar to Doppler but, in addition, can image the entire cardiac volume and the regurgitant jet at the valve plane.