[Rigid registration and fusion between SPECT and MRI/CT based on external fiducial alignment]

A convenient and effective method of rigid registration and fusion between SPECT and MRI/CT which is based on external fiducial alignment system is designed. After thresholding the image, many image processing arithmetics such as erosion, dilation are used to ensure the corresponding points which will be used to registrate. Then these points are used to minimize the cost function. In this way, an optimal rigid transform is gotten to registrate the images accurately and fuse them well. Error in the registration and fusion is reduced furthest by well designing the N-shape bracket which is used as the external fiducial alignment system and also by limiting the relative displacement between the bracket and the patient. Experimentation shows that this method can realize the registration and fusion of SPECT and MRI/CT effectively.