CONSTITUTION: A communication I/F 12 acquires a plurality of tomographic images corresponding to a plurality of positions in an extension direction of a reference axis penetrating a patient's body, each of which indicates a cross section orthogonal to the reference axis. The plurality of acquired body axis tomographic images are temporarily stored in a DRAM 22. A CPU 14 displays one of the plurality of body axis tomographic images stored in the DRAM 22 on a monitor 20, and updates the body axis tomographic image on the monitor 20 in response to a paging operation. The CPU 14 also measures a time for an image reading doctor to face a monitor screen, namely, a time of observation by the image reading doctor for each body axis tomographic image, and extracts part of the body axis tomographic images based on the measured time of observation.EFFECT: Since a body axis tomographic image whose time of observation is long can be regarded as an image of interest in which an image reading doctor has shown interest, it is possible to improve efficiency of image reading auxiliary work in which images of interest are integrated, by extracting part of the body axis tomographic images based on the time of observation.SELECTED DRAWING: Figure 1【構成】通信Ｉ／Ｆ１２は、患者の身体を貫く基準軸の延在方向における複数の位置にそれぞれ対応しかつ基準軸に直交する断面を各々が表す複数の断層画像を取得する。取得された複数の体軸断層画像は、ＤＲＡＭ２２に一時的に格納される。ＣＰＵ１４は、ＤＲＡＭ２２に格納された複数の体軸断層画像のいずれか１つをモニタ２０に表示し、モニタ２０の体軸断層画像をページング操作に応答して更新する。ＣＰＵ１４はまた、読影医がモニタ画面と向き合う時間つまり読影医による観察時間を体軸断層画像毎に測定し、測定された観察時間に基づいて一部の体軸断層画像を抽出する。【効果】観察時間が長い体軸断層画像は読影医が関心を示した関心画像とみなすことができるため、観察時間に基づいて一部の体軸断層画像を抽出することで、関心画像を纏める読影補助作業の効率化が図られる。【選択図】図１
