Real-time 3-dimensional echocardiographic evaluation of left ventricular volume: Correlation with magnetic resonance imaging - A validation study

Background. The purpose of our study was to validate the ability of real-ti me 3-dimensional echocardiography (RT3D) to measure cardiac volume. Methods: We studied 25 patients with various cardiac disorders who had a re gular heart rhythm and a good precordial echocardiographic window. Each pat ient underwent complete transthoracic echocardiography (TTE), RT3D, and mag netic resonance imaging (AM) studies. Left ventricular dimension was calcul ated from slices of the whole left ventricle obtained by 7 different equidi stant azimuth tilts. Planimetry of the endocardial (for volume data) and ep icardium (for mass data) surface was performed for each azimuth tilt. The l eft ventricular end-diastolic volume (LVEDV) and the left ventricular end-s ystolic volume (LVESV) were calculated. The cardiac mass data were derived with the formula (Epicardial volume - LVEDV) x 1.055. The parameters; of LV EDV, LVESV, stroke volume, ejection fraction, and cardiac mass were compare d with those derived from NM. Results. No statistically significant differences were found between the da ta from RT3D and MRI (P greater than or equal to .05). Good correlations we re found between these two methods for left ventricle volume and mass measu rements (r from 0.92 to 0.99). However, a weaker correlation was found with larger chamber sizes because extrapolation was necessary for the volume of myocardial segments that were not covered by the small sector angle. Conclusions: For data acquisition, RT3D is faster than either TTE or MRI. I t is also better than MRI for measuring cardiac volume and mass. To improve results with larger cardiac chamber sizes, enlargement of the sector angle will be necessary.