Normal left ventricular volumes and ejection fraction: assessment with quantitative digital cardioangiography

The aim of this study was to assess the accuracy and precision of a digital angiography system, the General Electric DX system, as compared to conventional left ventricular cineangiography. After a phantom study, sixty patients with normal coronary arteries and normal left ventricles (LV) were studied. The LV contours were manually traced from raw or subtracted digital runs and from the cine films in an independent manner. A regression formula was used to adjust the DX derived data to the cine film results (Vcorrected = 0.693 Vmeasured + 8.65 ml). There was an excellent correlation between the two methods in the end-diastolic volume index (r = 0.97, sd = 4.2 ml/m2), the end-systolic volume index (r = 0.95, sd = 2.7 ml/m2), the stroke volume index (r = 0.93, sd = 4.1 ml/m2), and the ejection fraction (r = 0.85, sd = 3.45%). We conclude that manual tracing of LV contours from either raw or subtracted digital images provides reliable and accurate measurement of LV volume and ejection fraction.