A medical image diagnosis apparatus according to an embodiment includes a lumen image generating unit, a running line generating unit, an image synthesizing unit and a control unit. The lumen image generating unit generates a lumen image depicting a shape of a lumen having a branch based on volume data. The running line generating unit generates a plurality of running lines based on the shape of the lumen. The image synthesizing unit generates a synthetic image by superimposing, on the lumen image, the plurality of the running lines indicating moving paths of a viewpoint in a virtual endoscopy image. The control unit displays the synthetic image and controls the image synthesizing unit to perform depiction that distinguishes between a range of a running line along which a virtual endoscopy image is displayed and a range of a running line along which no virtual endoscopy image is displayed.