Reconstruction of 3D image datasets from X-ray cone-beam data

摘要

The invention is directed to a method for producing a 3D image dataset of an object (20) with an imaging system (1) having an X-ray source (4) for emitting photon rays in a cone beam and a detector (10) comprising a two-dimensional array of detector elements adapted for receiving photons emitted by the X-ray source, the method comprising: acquiring (100) a series of two-dimensional arrays of cone beam data from the detector (10) while the source (4) moves along a substantially planar trajectory (40) around the object to be imaged, the trajectory being described by a series of source points serially numbered by a counter parameter; and reconstructing a 3D image from the cone beam data by performing the following steps:
A) differentiating the cone beam data with respect to the counter parameter (») of the source trajectory at fixed ray direction (±) to produce a derivative of the cone beam data;
B) filtering the derivative with a Hilbert-like filter to produce filtered cone beam data;
C) either before step A), or after step B) multiplying the acquired cone beam data or the filtered cone beam data, respectively, with a redundancy weighting function; and
D) back-projecting the cone beam data to compute a 3D image dataset. The invention is also directed to an imaging system (1) and a computer program product.