A rendering algorithm based on ray-casting for medical images

Ray-casting algorithm is usually used in medical volume visualization, but there are a lot of limitations inherent to this algorithm, like high computational demand, low quality images, or a fixed classification. In contrast, real-time high quality volume rendering algorithms are still a challenge nowadays. We introduce here an efficient and accurate volume rendering algorithm for medical images, and this algorithm can achieve up to 2.5 fps on PCs for 512×512×482×2 Byte volume. The algorithm classifies volume data into the foreground voxels and background voxels, and the former voxels are resampled using the similar LOD (Layer of Detail) technique, then optical attribute of the resampling points is determined by a new method. This method is reasonably associated with the distance between the object and the viewpoint, as well as the object and the light source. In addition, the background voxels are displayed by the accelerated method based on space leaping resampling. The results show that interactive volume rendering can be implemented for most medical volume data on PCs. Meanwhile, tissues or organs can be displayed clearly, which is more coincident with the human vision.