| 摘要 |
A computerized tomographic apparatus is described in which the source produces a fan-shaped distribution of X-rays and the detectors extend across the distribution so as to respectively receive radiation propagated along different beams of the distribution. The source and detectors are rotated around a patient about an axis intersecting a desired cross-sectional slice of the patient. The beam paths, through the body slice, along which radiation is projected for any one source position are divergent, but output signals relating to the totality of beam paths irradiated during a considerable rotational movement of the source around the body can be sorted into sets relating to parallel beam paths, to assist in processing them. However the sets of paths exhibit non-uniformity of spacing which can cause difficulty if convolution processing is employed. In order to reduce or overcome this problem, the present invention provides that the spacing between adjacent beams varies across the distribution.
|
