3D images, such as CT, MRI and PET, are used in the medicine, and greatly contribute to improvement in medical diagnosis. On the other hand, since a 3D image has larger amount of data than that of a 2D image, it is also a fact that a radiologist's load is increasing. To decrease the radiologist's load, development of the effective technology to visualize a 3D image and to assist the detection of disease is required. Here, the recent topics of the reconstruction, visualization, and computer-aided diagnosis for 3D medical image are reviewed.