Patent ID: 6028314
Filing Date: 2000-02-22
Classification: A61B,H04N

Abstract:
A method for correcting image errors in an image produced by a penetrating radiation-sensitive detector, comprising the steps of:providing a penetrating radiation-sensitive detector having a scintillator on which said penetrating radiation is incident, and a solid-state photodetector which produces a detector image from light generated by said scintillator due to penetrating radiation being incident thereon, said penetrating radiation-sensitive detector having a memory effect due to persisting charge carriers therein exhibiting a chronological decay behavior;irradiating said penetrating radiation-sensitive detector with a first penetrating radiation dose;changing said first penetrating radiation dose, at a change time, to a second penetrating radiation dose and producing a detector image from said penetrating radiation-sensitive detector at said second penetrating radiation dose;producing a correction image from said penetrating radiation-sensitive detector at least at a time before said change time;providing a reference measurement detector comprising an optical radiation-sensitive detector having a chronological decay behavior comparable to the chronological decay behavior of said solid-state photodetector;providing a reference measurement optical radiation source;measuring a decay curve, representing said chronological decay behavior, from said penetrating radiation-sensitive detector synchronously with producing said correction image by optically irradiating said reference measurement detector with optical radiation from said reference measurement optical radiation source to obtain a decay curve from said reference measurement detector and using said decay curve from said reference measurement detector as said decay curve representing said chronological decay behavior of said solid-state photodetector;weighting said correction image with said decay curve to obtain a weighted correction image; andcorrecting said detector image produced at said second penetrating radiation dose by subtracting said weighted correction image therefrom.