A method for automated extraction of the aorta area from 3D abdominal X-ray CT images without contrast medium by using edge information

摘要

We have already developed a method for extracting aorta areas in abdominal CT images. In this method the region growing method was used. However mis-extraction was caused when aorta touched other organs extensively. Here we propose a new method for extraction of aorta areas to reduce the mis-extraction areas. The edge information and the medial line of the aorta are used in the proposed method. First, the minimum distance from the edge areas is calculated at each voxel. The obtained image is called the distance image. The spine area is also extracted to determine the position of the aorta using the anatomical relationship between spines and aortas. Second, the medial line of the aorta is extracted by tracing local maxima of the distance image using the position of the aorta obtained above. Finally, the aorta area is extracted by applying the reverse Euclidean distance transformation to voxels on the medial line. We applied the proposed method to eleven 3D abdominal X-ray CT images without the contrast medium, and showed that proper aorta areas were obtained.