1. A medical image diagnosis apparatus comprising: a volume rendering image generation part that generates, from volume data, a volume rendering image that represents blood vessel information inside a subject; a mask image-storage that stores fluoroscopic mask images; a real time fluoroscopic image generation part that acquires real time fluoroscopic images for each chronological sequence accompanying device insertion; a subtraction image generation part that generates a subtraction image by subtraction processing on the fluoroscopic mask image stored in said mask image storage and the real time fluoroscopic image acquired for each chronological sequence; a coil image generation part that generates a coil image from the fluoroscopic mask image; and an image composition part that generates a composite image of the volume rendering image, the subtraction image, and the coil image.