PROBLEM TO BE SOLVED: To substantially shorten the time required for search/extraction of a parallax image and to smoothly advance diagnosing, by narrowing the search range of two images used for stereoscopic observation like 1/2, 1/4 and 1/8, ... for instance.SOLUTION: A viewer terminal 16 handles a plurality of images obtained by tomosynthesis imaging. By a right or left range selecting button 68a or 68b of an image search window 65, the movement of an observation center to any one of a direction from a reference angle to a certain irradiation angle in an irradiation angle and an opposite direction is selected. A search processing unit 58 narrows the search range of the parallax image to the range from the observation center selected this time to the past observation center closest to the observation center selected this time in the case that there is the past observation center selected by the previous time in the direction selected by the respective range selecting buttons 68a and 68b, and narrows the search range of the parallax image to the range from the observation center selected this time to an irradiation position at the end of the direction selected this time in the case that there is no observation center selected by the previous time in the direction selected by the respective range selecting buttons 68a and 68b. The central part of the narrowed search range is set to a new observation center.【課題】診断をより円滑に進めること。【解決手段】ビューア端末１６はトモシンセシス撮影で得られた複数の画像を扱う。画像検索ウィンドウ６５の右または左範囲選択ボタン６８ａ、６８ｂで、照射角が基準角からある照射角に向かう方向、または反対方向のいずれに観察中心を移動させるかを選択させる。検索処理部５８は、各範囲選択ボタン６８ａ、６８ｂで選択された方向に前回までに選択された過去の観察中心がある場合は、今回選択された観察中心から、今回選択された観察中心に最も近い過去の観察中心までの範囲に視差画像の検索範囲を絞り込み、各範囲選択ボタン６８ａ、６８ｂで選択された方向に前回までに選択された観察中心がない場合は、今回選択された観察中心から、今回選択された方向の端の照射位置までの範囲に視差画像の検索範囲を絞り込む。絞り込んだ検索範囲の略中心を新たな観察中心に設定する。【選択図】図５
