GPU based high-quality Maximum Intensity Projection using clipping plane re-rendering method

Abstract

Maximum Intensity Projection (MIP) is a volume rendering technique which is used to extract high-intensity value along the corresponding viewing ray. It identifies patients’ anatomical structures from MR or CT data sets. Recently, it becomes possible to generate MIP images with interactive speed by using Graphic Processing Unit (GPU) even in large volume data sets. As we can observe volume data sets in many arbitrary directions, usually, volume boundary plane is obliquely crossed with view-aligned texture plane. There is no data value in the outer of volume data boundary therefore the Nyquist frequency at the boundary becomes high. Since the sampling distance is not increased at volume data boundary in volume rendering, the aliasing problem due to data loss exists. If numbers of slices are increased to solve the aliasing problem for reducing sampling distance, it will decrease the rendering speed, too. In this paper, we propose a new method to re-render volume boundary planes. Our method improves image quality to reduce sampling distance near volume boundary which is high frequency area. On the other hand, MIP is independent of sampling order and increasing numbers of slices do not degrade image quality by using our method. Image quality is improved without increasing rendering time since it is only 6 clipping planes are needed for re-rendering. In addition, our method can be successfully used to apply to Volume of Interest (VOI) or clip-plane.