A temporal subtraction image can be used for enhancing interval changes such as shapes of new lesions and the interval changes in existing abnormalities on medical images by removing most of normal structures. In order to detect the lesions in chest radiographs, the temporal subtraction technique based on X-ray image has been applied successfully to clinical cases. But there is no technique for image registration based on 3-D medical images until now. In this paper, we propose a new registration method for detecting the temporal changes from MDCT images based on analyzing the vector flow. The new method was applied to 5 clinical cases of MDCT images and satisfactory experimental results are obtained.
