Patent ID: 8619944
Filing Date: 2013-12-31
Classification: A61B,G01N,G06T

Abstract:
1. A method for determining attenuation coefficients for an object using a movable X-ray source and a detector, which is provided for recording projections, the method comprising: specifying a trajectory path for the movable X-ray source; specifying positions on the trajectory path for determining a derivative of projections recorded by the detector; specifying a plurality of scanning positions for each of the specified positions; following the trajectory path with the X-ray source and recording a projection for each scanning position of the pluralities of scanning positions; numerically calculating a projection derivative in relation to the trajectory path for each of the specified positions using the associated recorded projection for each scanning position of the pluralities of scanning positions; and determining attenuation coefficients for the object from the calculated projection derivatives using a theoretically exact or approximate rule for a reconstruction, wherein an interval between adjacent scanning positions that belong to the same plurality of scanning positions is smaller than an interval between adjacent scanning positions that belong to different pluralities of scanning positions.