Medical image 3D reconstruct is an important application filed for volume rendering

for it special using

it required fast interactive speed and high image quality. Ray casting is a widely used basic volume rendering algorithm. It can get high quality image but the rendering speed is very slowly. In order to improve its rendering speed and apply it to medical image 3D reconstruct

a synthesized accelerate algorithm is proposed in this paper. Firstly

accelerate algorithms for ray casting are fully studied and compared. Secondly

proximity clouds algorithm has been selected and extended to continuous ray casting. Then the synthesized accelerate algorithm base on ray coherence has been proposed. Finally

the algorithm is realized on PC platform. Four data sets are used for test at two different image resolutions. The result shown that compare with standard ray casting algorithm

the accelerate algorithm not only improve the rendering speed for nearly ten times but also bring no depress on image quality. At 512×512 image resolution

a nearly real time interactive speed has been get. It gives a more capability method for the application of medical image 3D reconstruct.