A multicenter validation of an active contour‐based left ventricular analysis technique

Quantitative analysis of functional cardiac magnetic resonance (MR) images has been limited by the lack of well-validated, semiautomatic, methods for rapid analysis. We describe the evaluation of a DICOM-compatible PC-based parallel-processing tool, for cardiac magnetic resonance analysis (CAMRA), which supports semiautomatic image mensuration using an active contour model-based algorithm. The CAMRA software was used to analyze data from 12 patients in a multicenter acquisition and analysis trial to compare semiautomatic contour detection with manual planimetry of the left ventricular endocardium from short-axis, breath-held, cine gradient-echo images. There was excellent agreement between the manual and semiautomatic measurements of global left ventricular function, with no significant (P = 0.32) difference in the determination of ejection fraction (−0.9 ± 3.1% [mean difference ± 1 standard deviation]). There was no significant interobserver difference in the semiautomatically measured ejection fraction. Additionally, a single observer completed the analysis on data from 30 patients and found no significant (P = 0.05) difference in the determination of ejection fraction (−1.3 ± 3.5% [mean difference ± 1 standard deviation]). The CAMRA software demonstrates the capability for the reproducible evaluation of global left ventricular function in cardiac patients, with adequate interobserver reproducibility for use in multicenter trials. J. Magn. Reson. Imaging 2000;12:232–239. © 2000 Wiley-Liss, Inc.