Quantitative Measurement of Mitral Regurgitation: Comparison between Echocardiography and Cardiac Magnetic Resonance Imaging
Bunyapon Sukpraphrute MD*, Srisakul Chirakarnjanakorn MD*, Khemajira Karaketklang MPH***, Ahthit Yindeengam BSc**, Rungroj Krittayaphong MD*
Affiliation : * Division of Cardiology, Department of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Department of Research Promotion, Siriraj Hospital, Mahidol University, Bangkok, Thailand *** Department of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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
