PROBLEM TO BE SOLVED: To provide a technique which improves a resolution of an X-ray image in an X-ray imaging apparatus which can carry out various X-ray imaging having different ranges of X-ray irradiation.SOLUTION: The X-ray imaging apparatus 100 includes an X-ray generator 13 having a cathode 91 and an anode 92, an X-ray generating part 10 for outputting an X-ray beam from the X-ray generator 13 and an X-ray detecting part 20 for detecting the X-ray beam. The X-ray generating part 10 and the X-ray detecting part 20 are opposed to each other with an object to be imaged held between them and turned around the object to be imaged to carry out an X-ray imaging. The X-ray imaging apparatus 100 controls a regulating part 15 to regulate the transmission of X rays so that a focal size of the X-ray beam BX2 during an X-ray CT imaging of a relatively narrow area R2 to be imaged shown in Fig.12(b) is smaller than a focal size of the X-ray beam BX1 during X-ray CT imaging of a relatively wide area R1 to be imaged shown in Fig.12(a).COPYRIGHT: (C)2012,JPO&INPIT【課題】X線の照射範囲が異なる種々のX線撮影を実行可能するX線撮影装置において、X線画像の解像度を向上する技術を提供する。【解決手段】X線撮影装置100は、陰極91と陽極92とを含むX線発生器13を有し、前記X線発生器13からX線ビームを出射するX線発生部10と、X線ビームを検出するX線検出部20と、前記X線発生部10と前記X線検出部20とを、前記被写体を挟んで互いに対向させつつ、前記被写体周りに旋回させてX線撮影を行う。X線撮影装置100は、規制部15を制御することにより、図12(b)に示す比較的狭い撮影対象領域R2のX線CT撮影時のX線ビームBX2の焦点サイズを、図12(a)に示す比較的広い撮影対象領域R1のX線CT撮影時のX線ビームBX1の焦点サイズよりも小さくなるようにX線の透過を規制する。【選択図】図12
