[Noninvasive assessment of aortic and mitral valve insufficiencies with dynamic magnetic resonance tomography].

Dynamic magnetic resonance imaging (MRI) was performed in patients with aortic regurgitation (N = 14) and/or mitral regurgitation (N = 13), documented and graded for severity by angiography. Eight healthy persons were studied for comparison. Turbulent retrograde blood flow through incompetent valves causes signal loss of blood, thus permitting detection of the valvular defect. To determine the severity of regurgitation by dynamic MRI, several parameters were analyzed, including the number of slices with visible signal loss, the time course of the signal loss, and its maximal area and maximal volume. All regurgitant lesions were visualized in dynamic images. The area of signal loss correlated well with the angiographic severity of aortic and mitral regurgitation. A slightly better correlation was found for the volume of signal loss. Significant differences were also found for the other parameters. Analysis of the regurgitant jet, characterized by signal loss on dynamic MR images permits a semiquantitative assessment of the severity of regurgitant lesions of left-sided valves. Three-dimensional determination of the jet volume is a possible advantage of MRI compared to other noninvasive methods.