Method and system for reconstructing a 3d medical image

Abstract

The invention relates to a method for reconstructing a 3D medical image of a region of interest of a patient's body (P) lying on an operating table () with an X-ray imaging system comprising a motorized C-arm () supporting an X-ray source (), an X-ray image detector () and an anti-collision device (), comprising: —implementing a first path of the motorized C-arm without acquiring any X-ray image, said first path comprising at least two different angular positions around a rotation axis of the C-arm; —at each angular position of the C-arm along said first path, detecting with the anti-collision device () an external surface (S) of the patient's body and recording volumetric data of a patient's body portion enclosing the region of interest; —computing a volumetric model of the patient's body portion based on said volumetric data and on an estimation of X-ray absorption of patient's body tissues surrounding the region of interest, said volumetric model comprising a first part including the region of interest and at least one second part distinct from the first part, the first and second parts presenting different levels of X-ray absorption; —implementing a second path of the motorized C-arm and acquiring a 2D X-ray image at each angular position of the C-arm along said second path; —reconstructing a 3D medical image from the acquired 2D X-ray images, wherein said reconstructing comprises estimating, for each X-ray passing through a voxel of the 3D medical image, a level of X-ray absorption by the patient's body based on the volumetric model of the patient's body portion and adjusting a contribution of said X-ray to each voxel of the 3D medical image based on said estimated level.