| 摘要 |
Tomographic or sectional X-ray images (46) of a subject (32) are obtained rapidly by a method and apparatus that do not inherently require motion of the X-ray source (12) and detectors (13) or motion of the subject in order to generate the tomographic image data. In the source, a charged particle beam (17) is directed to a broad target plate (18) and raster scanned to produce a moving X-ray origin point (19). X-ray count values are obtained at a plurality of spaced apart detection points (D1, D2, D3, D4, D5, D6, D7) situated at the opposite side of the subject from the source. Successive count values from a first detection point are combined with successive count values from at least one other detection point that originated at a later time in the course of the raster scan to provide a sequence of composite data values. Display of an image of at least a portion of the raster scan which exhibits variations between successive values of the composite data provides an image in which data from a specific plane (31a, 31b) within the subject is emphasized while data from other planes is suppressed. The apparatus may be compact and inexpensive in comparsion with tomographic installations that are dependent on precisely controlled motion of components or the subject during scanning.
|
