EFFECTIVE VISUAL FIELD EXTRUSION DETECTOR IN X-RAY CT SYSTEM, REFERENCE CORRECTION DEVICE IN THE SAME AND X-RAY CT SYSTEM

摘要

PURPOSE: To detect the extrusion of a projecting position by performing self reference correction on the detection values of detectors for reference on both sides at every projecting angle along a turning circumference by its own detection value and discriminating the presence/absence of extrusion of the projecting angle for an examinee depending on whether or not a correction value shows zero. ;CONSTITUTION: Since information quantity obtained by a detector is set as a tomographic image in this X-ray CT system, the presence/absence of extrusion of the examinee to the outside of the effective visual field is judged at every projecting angle by an extrusion detecting means 7A. As a result, the fluctuation of X-rays at every projecting angle is corrected by the output of the detector for reference not transmitting the examinee by a reference correction means 8A. Then, omitted data is estimated by using an effective outside visual field estimation means 10. In other words, since judgement for extrusion is passed by using only projecting data, it is possible to discriminate the presence/absence of extrusion only by measurement by actual insertion of the examinee. Moreover, since only the projecting data is used, the extrusion can be detected simultaneously with the measurement.;COPYRIGHT: (C)1996,JPO