Quantitative Evaluation of Humeral Head Defects by Comparing Left and Right Feature

摘要

Humeral head (top of arm bone) defect has been diagnosed subjectively by physician. Therefore, it is required to develop a quantitative evaluation method of those defects. In this paper, we propose a quantitative diagnostic method for evaluating humeral head defects by comparing the shapes of the left and right humeral heads. The proposed method is composed of three steps. In the first step, the contour of humerus is extracted from a set of multi-slice CT images by using thresholding technique and active contour model. In the second step, the three-dimensional (3-D) surface model of humerus is reconstructed from extracted contours. In the third step, the reconstructed 3-D shape of left and right humerus is superimposed each other, and then the non-overlapped part is recognized as the defect part. This idea is based on the assumption that human bone structure is symmetrical each other. Finally, the shape of visualized defect part is analyzed by principal component analysis, and we consider that those obtained principal components and contributions represent the feature of the defect part. In this research, seven sets of shoulder multi-slice CT images are analyzed and evaluated.