Patent ID: 7559694

Claim:
A method of determining an acquisition geometry of an imaging system having a source of radiation and a C-type arm capable of shifting about three axes of rotation around an object, the method comprising: computing a calibration matrix for a calibration position of the imaging system; producing a projection matrix for an unspecified acquisition position of the C-type arm as a function of the calibration matrix, wherein the projection matrix brings about correspondence of a point of the object with an information content assigned to at least one projection pixel in a 2D image obtained at the unspecified acquisition position of the C-type arm; estimating a distortion undergone by the C-type arm at the calibration position by comparing the calibration matrix with the projection matrix to deduce a basic corrective term; computing a corrective term of the projection matrix for the unspecified acquisition position of the C-type arm by interpolating the basic corrective term; and correcting the projection matrix for the unspecified acquisition position of the C-type arm with the computed corrective term.