X=ray imaging system with amorphous silicon detector - with the detector surface divided into areas of varying resoltuion by electronically combining pixels into small or large groups

摘要

An X-ray imaging system with a amorphous silicon (Si:H) detector matrix. The detector comprises a number of sub-detectors (A-D), each of which has different resolution. The sub-detectors form part of the whole unit and are associated with a scintillator of constant resolution. The pixel concentration (A-D) for each sub-detector is equal and their varying resolution is obtained by use of parallel switching of neighbouring pixel columns and rows. A higher resolution scintillator (4) is associated with one sub-detector (B) and its resolution is matched to the scintillator. The high resolution sub-detector (B) can be operated with high or low frequency. An alternative system involves the overlaying of a second detector (higher) resolution to the first detector. The surface of the second detector is smaller than thant of the first detector. Different numbers of sub-detectors are possible, typically nine each with different areas of pixel concentration. Electronic means for surpressing aliasing are provided.