Image reconstruction method for computer tomograph in spiral scan mode

摘要

The image reconstruction method for a computer tomograph (1) working in a spiral scan operation mode, includes the step of shifting an examination subject (P), accommodated on a patient examination table (6), and a measuring system, rotating around the patient examination table, relatively w.r.t. each other, during operation of the computer tomograph. The measuring system comprises an X-ray source (3) and one, to it oppositely arranged, radiation receiver (5), whereby during operation of the computer tomograph an X-ray bundle (4) is emitted by the X-ray source, which hits on the radiation receiver. Spiral weakening values (S) are measured during circulation of the measuring system around the examination subject, which are evaluated in a calculation unit (8). A weighting method is used for the determination of weakening values (S( alpha , beta )) for the reconstruction of images of even body layers of the examination subject. The weighting method is utilized with a superimposition of spiral weighing factors, allowing for freely selectable parameters of amount of superimpositions, distance of the superimpositions, and intensity of contribution of each superimposition.