Abstract: Objective?To evaluate the accuracy of results of heart functions determined by 64-slice multi-detector row computed tomography (64-MDCT) in patients with single valvular insufficiency leision in left ventricle. Methods?58 patients with single valvular insufficiency leision in left ventricle were enrolled in this study. Their heart functions were assessed by magnetic resonance imaging (MRI)， 64-MDCT and echocardiography (Echo) respectively. The assessed parameters included left ventricular end-diastolic and end-systolic volume （LVEDV,LVESV）, stroke volume (LVSV), ejection fraction(LVEF), and effective ejection fraction(eLVEF). The correlations between eLVEF and some clinical indicators, such as cardiopulmonary bypass time (CPBT), ventilation time (VT), vasoactive drug used time (VDUT), and length of ICU stay (ICUST) were analyzed. Results?No significant differences were found in the parameters measured by 64-MDCT, Echo and MRI. A strong correlation between 64-MDCT and MRI (r: 0.79-0.92) was found with all of the parameters. The eLVEF measured by 64-MDCT and MRI correlated with CPBT, VT, VDUT and ICUST well (r: 0.56-0.84). Conclusion?64-MDCT is a rapid, accurate and cheap choice for assessing heart functions of patients with single valvular insufficiency leision in left ventricle. eLVEF is a good predictor for the outcomes of operations.