The simulation picture whose precision is high regardless of the presence of the past record which past photographed the suffering inspection person without preparing the enormous sample picture and the noise pattern picture, is offered. Past of the suffering inspection body the picture or the original picture which photographed human body phantom is input and (S201 - 203), the body thickness of the suffering inspection body is presumed and (S204), the body which is presumed thick and equivalence the water equivalent thick approximate model is calculated (S205). It calculates the noise quantity which it should add to the original picture and on the basis of the difference of the picture noise quantity and the aforementioned target picture noise quantity being included in the original picture, the addition projection data which added the noise quantity which it should add to the aforementioned original picture in the standard projection data and that standard projection data which are the projection data of the approximate model which is not noise (S208), on the basis of the approximate model, and, it draws up (S209). And, on the basis with of the standard projection data and the aforementioned addition projection data, the noise picture which includes the noise quantity which it should add to the original picture is reconstructed and the simulation picture draws up & is indicated (S210), this in addition to the original picture (S211).膨大なサンプル画像やノイズパターン画像を用意することなく、被検者を過去に撮影した履歴の有無にかかわらず精度の高いシミュレーション画像を提供する。被検体の過去画像または人体ファントムを撮影した元画像を入力し(S201~203)、被検体の体厚を推定して(S204)、推定された体厚と等価な水等価厚を近似モデルを算出する(S205)。元画像に含まれる画像ノイズ量と前記目標画像ノイズ量との差に基づいて、元画像に加算すべきノイズ量を算出し(S208)、近似モデルに基づいて、ノイズがない近似モデルの投影データである基準投影データと、その基準投影データに前記元画像に加算すべきノイズ量を加算した加算投影データと、を作成する(S209)。そして、基準投影データと前記加算投影データとに基づいて、元画像に加算すべきノイズ量を含むノイズ画像を再構成し(S210)、これを元画像に加えてシミュレーション画像を作成・表示する(S211)。
