High-quality intraoperative volume rendering in surgical navigation

In the past thirty years, with the tremendous development of computer graphics, various techniques have been proposed to solve problem of medical images, like CT and MRI data, visualization[1][2]. These techniques include iso-surface rendering [3][4], volume ray casting[5][6], texture-based volume rendering and so on. Sometimes it is necessary to perform medical grinding work to cure a person in operation like otitis. The corresponding parts around ears in application cannot display on the screen like it disappeared in real world. This paper will present a basic surgical navigation framework and provide a method to display the medical data volume dynamic in surgical navigation system. The visualization technique is direct volume rendering that do not extract any polygon meshes from volumetric data and can easily implement on GPU by OpenGL shader program. It also employs a mask to control whether this part of input model should display on the screen. The mask is as the same dimensions as the input volumetric data. To eliminate the jagged edges and achieve iterative rate, a 3D Gaussian filter loaded in shader program executed by GPU (Graphics Processing Unit).