PROBLEM TO BE SOLVED: To suppress decrease in energy resolution of a radiation imaging apparatus comprising a detector including a conversion part and a semiconductor element.SOLUTION: A radiation imaging apparatus comprises: a detector that includes a conversion part 108 converting incident radiation photons into optical photons or electric charge, and a pixel array 102 including a plurality of pixels 20 for acquiring a pixel value according to the optical photons or the electric charge； and a signal processing part 105 performing signal processing for correcting a radiation image subjected to energy discrimination based on the pixel value, using a correction coefficient according to a pixel value acquisition process model obtained by modelling a process for acquiring the pixel value based on the optical photon or the electric charge.SELECTED DRAWING: Figure 1【課題】変換部と半導体素子とを含む検出器を有する放射線撮像装置に対してエネルギー分解能の低下を抑制する。【解決手段】入射された放射線フォトンを光フォトン又は電荷に変換する変換部１０８と、前記光フォトン又は電荷に応じた画素値を取得するための複数の画素２０を含む画素アレイ１０２と、を含む検出器と、前記光フォトン又は電荷に基づいて前記画素値を取得する過程をモデル化した画素値取得過程モデルに応じた補正係数を用いて、前記画素値に基づくエネルギー弁別された放射線画像の補正のための信号処理を行う信号処理部１０５と、を有する。【選択図】図１
