1. An image diagnostic processing device configured to judge whether an anatomic abnormal region exists in an image representing the inside of a subject, the device comprising: a processing unit configured to perform a thresholding-process with respect to the image to obtain a two-value image; a generating unit configured to generate a penalty image from the two-value image; and a determining unit configured to fit a spherical or ellipsoidal model to the penalty image to determine an abnormal candidate region including ground glass opacity.