Quantitative axial oblique contrast left ventriculography: Validation of the method by demonstrating improved visualization of regional wall motion and mitral valve function with accurate volume determinations

To compare the relative merits of conventional and axial $\text{RAO}\text{LAO}$ angiography, we performed biplane left ventricular (LV) cineangiograms in 36 patients in both the conventional 30-degree $\text{RAO}\text{60}\text{-}\text{degree}$ LAO projection and in the axial 45-degree $\text{RAO}\text{60}\text{-degree}\text{LAO}\text{25}\text{-degree}$ cranial projection, in random sequence. LV volumes were calculated by a computerized system utilizing modification of the area-length method. End-diastolic volume, end-systolic volume, and ejection fraction correlated closely between the two projections (r = 0.93, 0.95, and 0.86, respectively). The axial 60-degree LAO view projected the LV apex inferiorly, the LV outflow tract superiorly, reduced LV foreshortening, and “uncovered” the LV outflow tract in all cases. Segmental wall motion abnormalities of the ventricular septum, apex, and posterior wall were better evaluated by the axial 60-degree LAO view in patients with regional asynergy in these zones. The 45-degree RAO, compared to the 30-degree RAO view, allowed a true tangential view of the mitral valve and provided a large “clear area” between the mitral valve and descending aorta, which improved the ability to quantify mitral regurgitation. Thus, axial oblique LV angiography improves evaluation of LV regional wall motion and mitral valve function without compromising LV volume quantitation.