The diagnostic system, photographing the spectrum picture of the specified wave length territory in inside the coelom, to acquire spectrum picture photographing expedient and the spectrum graphics data which obtain the spectrum graphics data, to calculate the index value which shows the territory where the possibility of being the lesion section from the said spectrum graphics data is high forming the lesion section extraction picture which is based on the said index value, to possess with the image processing expedient which it outputs and the monitor where the lesion section extraction picture is indicated, image processing expedient to designate the spectrum graphics data as intended variable concerning each pixel of the spectrum picture, absorption quality of light of the oxygenation hemoglobin and light of the restoration hemoglobinMultiple regression analysis is done absorption quality as an explanatory variable, index value is calculated on the basis of the density of the oxygenation hemoglobin and the restoration hemoglobin.診断システムが、体腔内において所定波長領域の分光画像を撮影して分光画像データを得る分光画像撮影手段と、分光画像データを取得し、該分光画像データから病変部である可能性が高い領域を示す指標値を求め、該指標値に基づいた病変部抽出画像を生成して出力する画像処理手段と、病変部抽出画像が表示されるモニタとを有し、画像処理手段は、分光画像の各画素について、分光画像データを目的変数とし、酸素化ヘモグロビンの光の吸収特性及び還元ヘモグロビンの光の吸収特性を説明変数として重回帰分析を行い、酸素化ヘモグロビン及び還元ヘモグロビンの濃度に基づいて指標値を求める。
