Image reconstruction technique for a computed tomography system

摘要

A computed tomography apparatus includes a gantry rotatable about an object being imaged, an X-ray source mounted on said gantry in opposing relationship to an array of X-ray detectors. An X-ray controller causing emission of X-rays from the X-ray source to shift between the two focal spots to produce first and second sets of projection data. X-rays are emitted from a first focal spot of the source while one projection of the object is acquired. Then the operation of the source is altered to emit X-rays from a second focal spot and the gantry is rotated by one-half the pitch of the detectors. Another projection is acquired at the new gantry position. Additional projections are acquired by alternately emitting the X-ray beam from the two focal spots and advancing the gantry by equivalent amounts between each acquisition. Data samples of the projections acquired by emission form the first focal spot are interleaved with data samples from projections made using the second focal spot to produce a resultant group of projections. An image is reconstructed from the resultant data array.