The present invention relates to a digital tomographic image synthesizing system, in which a bi-section search method is applied to reconstruct a three-dimensional image with projection data obtained by moving an X-ray tube at a limited photographing angle, The present invention relates to a method of reconstructing an image using a half-search method in a digital tomographic image synthesis system, which enables short-time exponentially shortening reconstructed sectional images and quick diagnosis.The present invention relates to an X-ray tube for irradiating X-rays, a detector for detecting a tomographic image for tomographic image synthesis (for tomosynthesis), a reconstructing apparatus for reconstructing a tomographic image for multiple tomographic images, Wherein the image processing unit performs the half search method for the x-coordinate when the virtual point where the X-ray reaches the detector is divided by the x-coordinate and the y-coordinate, in the 3D tomographic image synthesis system An x coordinate calculation step of calculating an x coordinate of an X-ray on a detector； The y-coordinate calculation step of calculating the y-coordinate of the X-ray on the detector by performing the half search method for the y-coordinate when the virtual point at which the X-ray reaches the detector is divided by the x-coordinate and y-coordinate； the x coordinate of the X-ray on the detector obtained in the x coordinate calculation step and the y coordinate of the X-ray on the detector obtained in the y coordinate calculation step are applied to derive the final coordinates.본 발명은, 디지털 단층영상합성 시스템에서, X선관이 제한된 촬영 각도를 움직이며 획득한 투영데이터로 3차원 영상재구성시, 이분검색방법(Bi-section search method)을 적용하여, 재구성 시간을, 기존방식과 비교하여, 기하급수적으로 단축시킴으로써, 빠른 시간에 재구성 된 단면영상을 확인하여 진단을 빠르게 할 수 있게 하는, 디지털 단층영상합성 시스템에서의 이분검색방법을 이용한 영상재구성 방법에 관한 것이다.본 발명은 X선을 조사하는 X선관, 복수의 단층영상합성용(트모신세시스용) 단층 화상을 검출하는 검출기,복수의 단층영상합성용 단층 화상을 재구성하여 X-선 투영 영상을 생성하는 화상처리부를 포함하는 디지털 단층영상합성 시스템의 3차원 영상재구성 방법에 있어서, X-ray가 검출기에 도
