Rendering Tomographic Volume Data: Adequacy of Methods for Different Modalities and Organs

A large variety of different algorithms for rendering radiological volume data has been described in the past. It has turned out that not every method is equally well suited for all kinds of modalities and organs. We therefore compare algorithms for different applications. The algorithms include Z-buffer gradient shading, gray level gradient shading, transparent gray level gradient shading, and two mutations of the marching cubes algorithm. The object classes are bone (CT), head (MRI), heart (MRI), vessels (MRI), ultrasound, and isodoses in radiotherapy. Properties of the algorithms, such as the achieved realism, the flexibility, and the computational cost are discussed. As a general result we found that the best visualization is achieved when different algorithms appropriate to the objects can be applied within one image.