To perform a more accurate and detailed diagnosis of a brain disease, a diagnosis server of the brain disease diagnosis system for diagnosing a brain disease of an examined person includes: an acquiring unit for acquiring a brain image of the examined person so as to obtain an acquired image； a region setting unit for setting a plurality of regions in the acquired image； an individual index value calculating unit for calculating an individual index value based on a pixel value of the acquired image, in each of the plurality of regions； a whole index value calculating unit for calculating a whole index value by weighting the individual index value of each of the plurality of regions； a diagnosis unit for diagnosing the brain disease of the examined person based on the whole index value； and an output unit for outputting information indicating a diagnosis outcome.本發明之目的在於更正確且詳細地進行腦部疾病之診斷。診斷就診者之腦部疾病之腦部疾病診斷系統1之診斷伺服器10包括：取得部11，其取得就診者之腦部圖像並作為取得圖像；區域設定部12，其於取得圖像中設定複數個區域；個別指標值算出部13，其針對複數個區域之各個區域，根據取得圖像之像素值而算出個別指標值；整體指標值算出部14，其藉由對複數個區域各自之個別指標值進行加權而算出整體指標值；診斷部15，其根據整體指標值而診斷就診者之腦部疾病；以及輸出部16，其輸出表示診斷結果之資訊。
