Transthoracic three-dimensional echocardiography in comparison with magnetic resonance imaging for determination of left ventricular mass in patientswith dilated cardiomyopathy

Conventional echocardiographic methods of measuring left ventricular mass ( LVM) are limited by assumptions of ventricular geometry and image plane pos itioning Three-dimensional (3D) echocardiography offers a promising new app roach for more accurate determination of LVM. This study was performed to c ompare LVM measurement by one- (1D), two- (2D), and 3D echocardiography wit h magnetic resonance imaging (MRI) in patients (pts) with dilated cardiomyo pathy (DCM). 36 pts (age 18-74) with DCM underwent imaging by conventional 1D and 2D ech ocardiography as well as transthoracic 3D echocardiographic data acquisitio n. Also, pts were imaged with cardiac MRI. Due to echocardiographic and MRI : quality and because of exclusion criteria's for MRI, it was not possible to accomplish each LVM determination method for each patient. LVM was deter mined by Devereux and area-length algorithm for the conventional echocardio graphy. 3D echocardiographic data was calculated after manual delineation o f endo- and epicardial boundaries - slice by slice (5 mm)- in 3 perpendicul ar cut planes. LVM was determined by multiplying the myocardial volume by t he specific density of the; myocardium. To determine LVM in MRI, the even s ummation of slices method for myocardial volume measurement was used define d by the endo- and epicardium in short axis images. There was no significant correlation (r = 0.42) for measuring LVM between I D echocardiography and MRI in pts with DCM. A significant correlation was o btained between 2D (r = 0.64, p < 0.01) echocardiography and MRI as well be tween 3D (r = 0.78, p < 0.01) and MRI in determination of LVM. Compared wit h 1D and 2D echocardiography, the 3D analysis achieved a significantly high er agreement with the results of the MRT (1D: 399.2 g, 2D: 285.9 g, 3D: 172 .6 g versus MRT: 199.1 g). Interobserver variability was 5.1% for measuring LVM by 3D echocardiography (1D: 11.2%, 2D: 9.1%). In conclusion, in pts wi th DCM the determination of LVM was incompletely characterized by 1D and 2D echocardiography compared with results of MRI. The best correlation and hi gh agreement for determination of LVM was obtained with 3D echocardiography compared with MRT.