1. A medical image processing apparatus comprising: an image storage memory configured to store data of an image including an aneurysm in an object; processing circuitry configured to extract a blood vessel wall region from the image; calculate at least one of a blood vessel diameter change rate, a blood vessel curvature, and a blood vessel flattening ratio at each of a plurality of discrete points on the blood vessel wall region based on the extracted blood vessel wall region; extract a plurality of feature points from the plurality of discrete points based on the at least one of the blood vessel diameter change rate, the blood vessel curvature, and the blood vessel flattening ratio; and decide a range for indwelling of a stent graft for the aneurysm in accordance with the extracted feature points; and a display configured to superimpose and display the range on the stored image.