PROBLEM TO BE SOLVED: To reduce radiation exposure on a subject in determination of an imaging direction.SOLUTION: A medical image processing device according to an embodiment of the present invention comprises an extraction unit and an identification unit. The extraction unit extracts a parent vessel and an aneurysm from three-dimensional image data. The identification unit identifies a direction of imaging by an x-ray diagnostic device on the basis of: the inner product of the normal vector of a neck surface which is a boundary between the parent vessel and the aneurysm and a projection direction vector set in the three-dimensional image data; and the inner product of the core wire vector of the parent vessel and the projection direction vector.SELECTED DRAWING: Figure 3【課題】撮影方向を決定する際に被検体への被曝を低減すること。【解決手段】実施形態の医用画像処理装置は、抽出部と、特定部とを備える。抽出部は、3次元画像データから親血管と瘤とを抽出する。特定部は、前記親血管と前記瘤との境界であるネック面の法線ベクトルと、前記3次元画像データにおいて設定した投影方向ベクトルとの内積、及び、前記親血管の芯線ベクトルと、前記投影方向ベクトルとの内積に基づいて、X線診断装置による撮影方向を特定する。【選択図】図3