Detection of blood vessels on CTA images of the legs

The disease that causes the obstruction of blood flow by arteriosclerosis and thickening of the arteries in the legs is called arteriosclerosis obliterans (ASO). The early detection and treatment of ASO is very important issue in the medical field. Recently, by using computer aided diagnosis (CAD), physicians can easily detect the blood vessel on the image and displaying the results by use of the system. One of the techniques for analyzing the blood vessels widely used in medical imaging is computed tomography angiography (CTA). The CTA uses three dimensional (3-D) imaging technologies. It also produces a clear image of main blood vessels throughout the body by using contrast media. The 3-D blood vessel image is made the volume data obtained by the CTA. By using 3-D image, we can observe the image from multi aspect. And also, it leads to the improvement of the diagnosis accuracy. In order to diagnose a symptom of the ASO, we propose a method for visual screening technique by detecting blood vessel area on the images. In this paper, we have developed a technique for separation of bone region and blood vessel area in order to extract blood vessels from a CTA volume image. The proposed technique was applied to two real CTA cases and satisfactory results for segmentation of the blood vessels were obtained. Some experimental results are shown with discussions.