Imaging system with x-ray beam angulation compensation

摘要

In an X-ray imaging system, an arrangement is provided for readily aligning the system detector (20) with the X-ray beam field, i.e., the projection of the X-ray beam (30) into the plane of the detector (20). The arrangement is adapted for correcting or compensating for distortion which results from X-ray beam angulation, wherein the beam is projected toward the detector plane at an angle of less than 90°. Initially, the system X-ray tube (12) is positioned to project the X-ray beam (30) at a given beam direction angle φ. A beam width angle γ1 is then computed, from the given angle φ and from specified values of the source-to-image distance and the length of the projected beam field. Thereupon, an offset value is determined from γ1, φ and the source-to-image distance to locate the geometric center of the beam field, and the center of the detector is aligned therewith.