Background and Objective: Echocardiography is usually performed to quantify the severity of regurgitation. Magnetic resonance imaging (MRI) can also quantify mitral regurgitation. This study was performed to determine whether MRI can reliably quantify the severity of mitral regurgitation when compared with echocardiography.
Material and Method: The authors retrospectively studied patients who underwent cardiac MRI between January 2008 and January 2011. Echocardiography was performed within 3 months of MRI. Mitral regurgitation was quantified by 3 methods of MRI; 1) difference of left ventricular stroke volume and right ventricular stroke volume, 2) difference of left ventricular stroke volume and forward flow volume in ascending aorta and 3) calculation of regurgitation fraction from the ratio of area of regurgitant jet and area of the left atrium. Proximal isovelocity surface area was the echocardiography parameter for mitral regurgitation.
Results: Forty-three subjects (24 women and 19 men; 47 to 85 years of age) were enrolled. Mitral regurgitation grading by MRI (2nd method) was mild (n = 28) moderate (n = 11) and severe (n = 4). There was moderate correlation between echocardiography and MRI assessments of regurgitation volume as follows; (1) difference between left ventricular stroke volume and right ventricular stroke volume (r = 0.48, p = 0.016), (2) subtracting forward flow volume of ascending aorta from left ventricular stroke volume (r = 0.48, p = 0.012). There was also correlation between regurgitation volume by echocardiography and fraction of maximal area of regurgitant jet divided by the area of the left atrium (r = 0.72, p < 0.001)
Conclusion: Cardiac MRI compares favorably with echocardiography for quantifying mitral regurgitation severity.

Keywords: Mitral regurgitation, Magnetic resonance imaging, Mitral valve, Cardiovascular images