PURPOSE: A respiration-synchronized image acquisition method for computed tomography (CT) scanner is provided to analyze a photographed CT image without external factors, thereby preventing the deterioration of accuracy of photographing caused by the external factor. CONSTITUTION: A respiration-synchronized image acquisition method for CT scanner comprises the steps of: rotating and moving a gantry； obtaining sequentially a plurality of CT images by an X-ray detector while the gantry rotates (S12)； generating a difference image between each of the plurality of CT images and a previous CT image adjacent to each of the plurality of CT images (S13)； outputting a respiration synchronization signal if similarity between the difference images is more than a predetermined reference value, and setting a CT image corresponding the difference image in response to the respiration synchronization signal as a respiration synchronization image (S15-S17)； and completing the photographing if a plurality of respiration synchronization images for a subject is obtained at all predetermined angles (S18,S19). [Reference numerals] (AA) Start； (BB,DD) No； (CC,EE) Yes； (FF) End； (S11) Set an area of interest； (S12) Obtain sequentially a plurality of CT images； (S13) Generate a difference image between a previous angle image and the current angle image； (S14) Calculate a similarity level between difference images； (S15) Decide whether the similarity level is larger than a reference value； (S16) Output a respiration synchronization signal； (S17) Set a respiration synchronization image； (S18) Decide if a plurality of respiration synchronization images for a subject is obtained at all predetermined angles； (S19) Complete the photographing전산화 단층 촬영장치의 호흡동기 영상 획득방법을 공개한다. 본 발명은 갠트리 모터에 의해 회전되는 갠트리에 서로 마주보게 고정되어 단층 영상을 촬영하는 X-선 조사기와 X-선 검출기를 구비하는 전산화 단층 촬영장치의 호흡동기 영상 획득방법에 있어서, 갠트리가 회전되어 이동되는 단계, 갠트리가 회전되는 동안 X-선 검출기에 의해 복수개의 단층 영상이 순차적으로 획득하는 단계, 복수개의 단층 영상 각각과 복수개의 단층 영상 각각에 인접한 이전 단층 영상과의 차 영
