Influence of positional and angular variation of automatically planned short-axis stacks on quantification of left ventricular dimensions and function with cardiovascular magnetic resonance

PURPOSE: To theoretically and experimentally investigate the influence of the automated cardiovascular magnetic resonance (CMR) scan planning pitfalls, namely inaccurate positioning and tilting of short-axis (SA) imaging planes, on quantification of the left ventricular (LV) dimensions and function. MATERIALS AND METHODS: Eleven healthy subjects and eight patients underwent CMR. Manually and automatically planned SA sets were acquired. To obtain the quantitative measurements of LV function, one observer performed image analysis twice. The agreement between planning methods, as well as the decomposition of the total variation into interstudy and intraobserver components was measured. RESULTS: The decomposition of the total variation showed that the interstudy factor accounts for 70-85% of the total variation, while the rest is due to the intraobserver factor. Moreover, the relative contribution of the interstudy factor remains independent from errors in slice positioning and small angular deviation of SA stacks from the optimal orientation. Good agreement between the theoretical and measured variability factors was observed. CONCLUSION: Global LV function derived from the automatically planned CMR acquisitions yield accurate quantification of the human cardiovascular system. Inaccurate positioning and tilting of SA images does not affect the quantitative measurements of LV function. The computer-aided system for automated CMR has proven clinical applicability.