[Evaluation of left ventricular morphology and function by cardiac computed tomographic examination].

Usefulness of cardiac computed tomography (CT) in the evaluation of left ventricular (LV) morphology and function was studied in clinical practice. One hundred and forty-nine adult cases of various heart diseases were examined by GE scanner with ungated scans covering whole LV and ECG-gated scans. In gating examination, "long-axial" and "short-axial" slices were scanned and end-diastolic area (EDA), end-systolic area (ESA) and "mean" area (MA) were obtained in each slices. 1) With regard to LV morphology, wall thickening in HCM and wall thinning and mural thrombus in myocardial infarction were easily visualized. 2) LV "mean" volume (LVMV) was easily calculated from the sum of sliced LV volume of ungated scans. The LVMV was well correlated with end-diastolic volume (EDV) obtained by LV angiocardiography (LVG) (r = 0.91), though the former was somewhat smaller than the latter. EDV by CT obtained after the correction with MA/EDA from gating examination showed a better correlation (r = 0.95) and both EDV showed almost the same value. 3) LV ejection fraction (EF) was calculated by exchanging ESA/EDA to ESV/EDV in "long-axial" and "short-axial" gated slices, and "long-axial" EF, "short-axial" EF and mean of both were well correlated with LVEF of LVG (r = 0.73-0.79). 4) LVEF calculated from "long-axial" EDA and ESA by application of "area-length" method was also correlated with EF of LVG (r = 0.68), but these EDV and ESV were smaller than those of LVG due to shorter long-diameter of LV in CT. 5) LV muscle volume was calculated from sum of sliced muscle volumes of ungated scans covering LV, and LV mass was easily evaluated from LV muscle volume and specific gravity of LV muscle. This LV mass was well correlated with that of LVG (r = 0.90) and the absolute values were almost the same.