A total of 79 patients with mitral regurgitation (age 62 +/- 11 years, 45 men, 34 women) quantified by angiography was studied using color-Doppler imaging of isovelocity surface areas in the flow convergence region proximal to the regurgitant orifice (PISAs), of the jet cross-section at the level of the regurgitant orifice and of the regurgitant jet in the left atrium. The PISA-radii for the flow velocities (aliasing borders) of 28 and 41 cm/s, the cross-sectional jet area and the jet length, and relation of jet area to left atrial area were measured. The sensitivity for the detection of mitral regurgitation was at least 97% for the color-Doppler methods investigated in these patients in which a sufficient imaging was obtained. However, a sufficient imaging of the flow convergence region and the jet cross-section was not possible in about 5% of all patients. The PISA-radii for both flow velocities and the cross-sectional jet area correlated more closely with the angiographic grade (rSp = 0.79-0.80, p < 0.001) than the jet area (rSp = 0.39, p < 0.001), jet length (rSp = 0.37, p < 0.001), and relation of jet area to left atrial area (rSp = 0.31, p < 0.01) did. A correct differentiation of grades I to II from grades III to IV mitral regurgitation was provided in 93-95% of patients by the proximal flow convergence and by the cross-sectional jet area method and, at most, in 76% of the patients by the jet area method using the uncorrected jet area.(ABSTRACT TRUNCATED AT 250 WORDS)