Method and apparatus for reducing X-ray dosage in a spiral scan cone beam CT imaging system

摘要

A scanning and data acquisition method and apparatus for three dimensional (3D) computerized tomography (CT) imaging of an ROI in an object, wherein a reconstructed image is developed by calculating reconstruction data along a plurality of line segments L formed in cone beam data acquired on a detector at a plurality of source positions about the ROI. The endpoints of the line segments L formed in the cone beam data acquired at each of the source positions is determined by a data combination mask which is applied to the cone beam data. When acquiring cone beam data near the top or bottom edges of the ROI, a radiation blocking element is operated for blocking radiation directed toward the ROI, so that only that portion of the detector is exposed to radiation.