PROBLEM TO BE SOLVED: To provide an apparatus and a method which can allow concise analysis of a plaque by eliminating as a reference ROI to set as possible.SOLUTION: The average of pixel values within the reference ROI set up on an image is determined as a reference signal strength. The imaging condition for the image wherein the reference ROI is set up is stored together with the corresponding reference signal strength. Signal strength ratios are determined between the reference signal strength corresponding to the imaging condition which agrees with the imaging condition for the image wherein an analyze ROI is set up and pixel values within the analyze ROI. The signal strength ratios are based to operate information which indicates a state within the analyze ROI.COPYRIGHT: (C)2013,JPO&INPIT【課題】 参照ROIの設定をできるだけ省き、簡便にプラーク解析を可能とする。【解決手段】 画像上に設定された参照ROI内の各画素値の平均値を参照信号強度として求め、参照信号強度と参照ROIが設定された画像の撮像条件とを記憶し、解析ROIが設定された画像の撮像条件と一致する撮像条件に対応する参照信号強度と、解析ROI内の各画素値との信号強度比に基づいて、解析ROI内の状態を表す情報を演算する。【選択図】 図3
