PROBLEM TO BE SOLVED: To provide image reconstruction, minimizing the deterioration of spatial resolution, even when a gap is formed between detector modules in a slice direction of a radiation detector.SOLUTION: A radiation tomographic imaging apparatus comprises a radiation detector 3 in which a plurality of detector modules 30, each containing a plurality of detection elements 31, are arranged in a CH direction and an SL direction, and a gap GAP is formed between the detector modules 30 in the SL direction. In the radiation tomographic imaging apparatus, storage means is provided to store positional information of each individual detection element 31 of the radiation detector 3, and image reconstruction means applies weighted summation on each real data piece Pa1, Pa2 obtained by a plurality of detection elements a1, a2 locating near an intersection point c of a radiation path p passing through a pixel g to be reconstructed from a radiation focal point f and a detection plane k of the radiation detector 3, by weighting coefficients based on positional information Lc of the intersection point c and positional information La1, La2 of the detection elements a1, a2 stored in the storage means to generate projection data P of the radiation path p, and reconstructs the pixel g by using a three-dimensional image reconstruction method on the basis of the projection data P.COPYRIGHT: (C)2014,JPO&INPIT【課題】放射線検出器のスライス方向における検出器モジュール間に間隙が形成されていても、空間分解能を極力劣化させずに画像再構成する。【解決手段】複数の検出素子31を含む検出器モジュール30がCH方向及びSL方向に複数配設され、SL方向に検出器モジュール30間に間隙GAPが形成されている放射線検出器3を備えた放射線断層撮影装置において、放射線検出器3の個々の検出素子31の位置情報を記憶する記憶手段を備え、画像再構成手段が、放射線焦点fから再構成対象の画素gを通る放射線パスpと放射線検出器3の検出面kとの交差点cの近傍に位置する複数の検出素子a1,a2にて得られた各実データPa1,Pa2を、交差点cの位置情報Lcと記憶手段に記憶されている検出素子a1,a2の位置情報La1,La2とに基づく重み係数で加重加算して、放射線パスpの投影データPを生成し、これを基に3次元画像再構成法により画素gを再構成する。【選択図】図4
