1. A medical image diagnosis apparatus comprising: a designating unit that designates an imaging range of a subject from a projection image for designation of the imaging range; a specifying unit that specifies a specific spot on the projection image; a scanning control unit that performs scanning for generating a three-dimensional medical image of the subject on the basis of the imaging range designated by the designating unit; a region determining unit that finds out a three-dimensional target region from the three-dimensional medical image obtained by the scanning on the basis of the specific spot specified on the projection image; and a detection unit that detects a candidate for an abnormal part in the three-dimensional target region.