PROBLEM TO BE SOLVED: To assist an operator to implant a prosthetic valve at a correct position in a blood vessel without much trouble.SOLUTION: A medical image diagnosis device comprises: an imaging unit for capturing a medical image in parallel with a running direction of the blood vessel a display unit for displaying the medical image captured by the imaging unit a determination unit for determining whether the prosthetic valve in the medical image is in parallel with the running direction of the blood vessel or not an annunciation unit for announcing that the prosthetic valve is not in parallel with the running direction of the blood vessel when it is determined so and a storage unit for storing prosthetic valve information on an aspect ratio of the prosthetic valve. The determination unit finds the aspect ratio of the prosthetic valve based on the medical image displayed by the display unit (STEP S12), evaluates whether the found aspect ratio and the one from the prosthetic valve information are the same or not (STEP S13), and determines that the prosthetic valve is in parallel with the running direction of the blood vessel when evaluating that the found aspect ratio and that from the prosthetic valve information are the same and determines that the prosthetic valve is not in parallel with the running direction of the blood vessel when evaluating that the found aspect ratio and that from the prosthetic valve information are not the same.COPYRIGHT: (C)2013,JPO&INPIT【課題】手間をかけずに血管中の正確な位置に人工弁を留置するための支援を行う。【解決手段】医用画像診断装置は、血管の走行方向に平行な医用画像を撮像する撮像部と、その医用画像を表示する表示部と、医用画像中の人工弁が血管の走行方向に平行であるか否かを判定する判定部と、人工弁が血管の走行方向に平行でないと判定された場合その旨を報知する報知部と、人工弁の縦横比に関する人工弁情報を記憶する記憶部とを備え、判定部は、表示部により表示された医用画像から人工弁の縦横比を求め(ステップS12)、求めた縦横比と人工弁情報の縦横比とが同じであるか否かを判断し(ステップS13)、求めた縦横比と人工弁情報の縦横比とが同じあると判断した場合、人工弁が血管の走行方向に平行であると判定し、求めた縦横比と人工弁情報の縦横比とが同じでないと判断した場合、人工弁が血管の走行方向に平行でないと判定する。【選択図】図2