Left Ventricle Segmentation in Magnetic Resonance Images with Modified Active Contour Method

Abstract

Desired segmentation of the image is a pivotal problem in image processing. Segmenting the left ventricle (LV) in magnetic resonance images (MRIs) is essential for evaluation of cardiac function. Fo r the segmentation of cardiac M RI several methods have been proposed and implemented. Each of them has advantages and restrictions. A modified region-based active contour model was applied for segmentation of LV chamber. A new semi-automatic algorithm was suggested calculating the appropriate Balloon force according to mean intensity of the region of interest for each image. The database is included of 2,039 MR images collected fro m 18 children under 18. The results were co mpared with previous literatures according to two standards: Dice Metric (DM) and Point to Curve (P2C). The obtained segmentation results are better than previously reported values in several literatures. In this study different points were used in cardiac cycle and several slice levels and classified into three levels: Base, Mid. and Apex. The best results were obtained at end diastole (ED) in co mparison with end systole (ES), and on base slice than other slices, because of LV b igger size in ED phase and base slice. With segmentation of LV M RI based on novel active contour and application of the suggested algorithm for balloon force calculat ion, the mean imp rovement of DM co mpared to Grosgeorge et al. is 19.6% in ED and 49.5% in ES phase. The mean improvement of P2C co mpared with the same literature respectively for ED and ES phase is 43.8% and 39.6%.