PROBLEM TO BE SOLVED: To provide a radiographic apparatus capable of performing appropriate angiographic imaging while more reducing an exposure dose of a subject.SOLUTION: A moving speed detection unit 29 detects a moving speed of an X-ray irradiation field in an X direction as needed based on a moving speed of a top plate 3 in an X direction. An irradiation range calculation unit 31 calculates the length of the X-ray irradiation field in an X direction as needed based on the moving speed of the X-ray irradiation field. A collimator control unit 15 adjusts the width of the X-ray irradiation field as needed according to the calculated length so that the X-ray irradiation field is adjusted to a wide level automatically. As a result, even when a contrast medium moves fast, a region of interest can be reliably captured in the X-ray irradiation field. When the contrast medium moves slowly, an operator adjusts the moving speed S of the top plate 3 to a slow level so that the X-ray irradiation field is adjusted to a narrow level automatically. As a result, unnecessary exposure can be avoided. Thus, the region of interest can be captured in the X-ray irradiation field more reliably while an exposure dose of the subject is reduced more.SELECTED DRAWING: Figure 1【課題】被検体の被曝量をより低減しつつ好適な血管造影撮影を行うことのできるＸ線撮影装置を提供する。【解決手段】移動速度検出部２９はｘ方向における天板３の移動速度に基づいてｘ方向におけるＸ線照射野の移動速度を随時検出する。照射範囲算出部３１はＸ線照射野の移動速度に基づいて、ｘ方向におけるＸ線照射野の長さを随時算出する。コリメータ制御部１５は算出された長さに応じてＸ線照射野の広さを随時調整するので、Ｘ線照射野は自動的に広く調整される。その結果、造影剤が速く移動する場合であっても関心部位を確実にＸ線照射野内に収められる。造影剤の移動速度が遅い場合、術者は天板３の移動速度Ｓを遅く調節するのでＸ線照射野は自動的に狭く調整される。その結果、無用な被曝を回避できる。従って、関心部位をより確実にＸ線照射野の範囲内に収められるとともに、被検体の被曝量をより低減できる。【選択図】図１
