3D Soft-Tissue visualization Scheme of CT Images via Distance Transformation
LIN Yao,TIAN Jie,HE Hui guang()
In this paper, a new 3D soft tissue display scheme is proposed, which consists of four steps: image segmentation, distance transformation, peeling operation and volume rendering. Firstly, an image segmentation method is adopted to detect the contour of skin, and a new binary output image is produced. Secondly, to reduce the computation time, a new 3D Euclidean distance transformation algorithm was adopted to compute the distance map of the medical image. Thirdly, the image data of the scarfskin and subcutaneous fat of the specified depth is removed through peeling operation. Finally, in order to meet the requirement of real time interaction in the medical application, a new multi surface visualization method was adopted, whose rendering time is reduced by only projecting the voxels near the boundaries between the different tissues. Meanwhile, it improves the visualization quality by computing the normal of the point where the ray crosses the iso surface in the projected voxel. This scheme was implemented in the 3D medical image process and analysis system developed by our lab to display the soft tissue of the CT images. The experiment results show that the anatomical structure among the blood vessel, flesh and bone can be visible clearly, and this method has important practical value in clinical diagnosis.