PROBLEM TO BE SOLVED: To provide an X-ray CT (computed tomography) device by which an initiation timing of real scanning can be precisely and accurately detected even when there are a heart rate, respiration, and body motion of a subject after the initiation of the injection of a contrast agent.SOLUTION: The X-ray CT device 1 comprises: a pre-scanning control unit 51 which can perform pre-scanning without contrast agent an image generation unit 52 which can generate an image without contrast agent on the basis of a pre-scanned product a region setting unit 53 which can set, based on the image without contrast agent, an ROI (region of interest) and an expanded region that includes the ROI and a peripheral region thereof and is used for the determination as to whether or not a high-CT-value region exists a comparing unit 54 which can compare a CT value in the expanded region with a first threshold value an abnormality notifying unit 55 which, when it is determined that a CT value that is greater than a first threshold value exists in the expanded region based on the result of the comparison, notifies that effect a timing detection unit 58 which, when it is determined that the CT value that is greater than the first threshold value does not exist in the expanded region based on the result of the comparison, can detect the timing of the initiation of the real scanning in which the pixel value in the ROI is greater than a second threshold value after the initiation of the injection of a contrast agent and a real scanning control unit 59 which can perform the real scanning when the timing of the initiation is detected.COPYRIGHT: (C)2012,JPO&INPIT【課題】X線CT装置において、造影剤の注入の開始後に被検体の心拍、呼吸、及び体動があっても、本スキャンの開始タイミングを正確に精度よく検知すること。【解決手段】X線CT装置1は、非造影でプリスキャンを実行するプリスキャン制御部51と、プリスキャンを基に非造影画像を生成する画像生成部52と、非造影画像を基にROIと、ROI及びその周辺領域とを含み、高CT値領域が存在するかを判断するための拡大領域とを設定する領域設定部53と、拡大領域内のCT値と第1の閾値とを比較する比較部54と、比較の結果を基に拡大領域内に第1の閾値を超えるCT値が存在すると判断する場合、その旨を報知する異常報知部55と、比較の結果を基に拡大領域内に第1の閾値を超えるCT値が存在しないと判断
