An automatic aneurysm extraction algorithm in fused brain digital subtraction angiography images

Brain aneurysm is one of the most life-threatening events, which is associated with a high rate of mortality and disability. There are many factors, which specify the best treatment option for each particular patient. In this paper, an automatic computer-aided extraction algorithm for brain aneurysm, from fused digital subtraction angiography (DSA) images is proposed. In this algorithm, firstly, to remove vessel structure, morphological operations based on multi-directional structure elements and nonlinear diffusion filtering are used. Then, by applying circular Hough transform and region growing algorithms, the aneurysm extraction procedure is performed. In this step, to overcome to poor edge gradient of aneurysm, we define a labeled diffused image which specifies the region growing conditions. Finally, by using morphological operators, the aneurysm extraction performance of our algorithm is improved. In addition, the radius of extracted aneurysm is defined and reported as a geometric feature. The experimental results indicate that our proposed algorithm obtains accuracy rate of 77.5% for the aneurysm extraction on 30 abnormal cases.