Tomographic scanner and method.

摘要

A method and apparatus for computerized axial tomography (CAT) image reconstruction applicable to X-ray scanning of the human body. Successive series of calculations determine the values of a characteristic in defined segmented areas of an examination plane. A reduction in the time and equipment requirements for reconstruction calculations may thereby be effected. Images representative of the difference between the value of the characteristic at a reconstruction point and the average value of the characteristic in adjacent regions ( DELTA mu ) may be calculated and displayed from measurements taken within a localized contiguous region of the examination plane. Radiation dose to patients and computation time in X-ray computerized axial tomography scanning systems is thus reduced. Differential displays of the type described may be adjusted to image boundaries, in which case they do not suffer from gray scale resolution problems which are typical of prior art displays. Image artifacts attributable to interpolation errors may be reduced with negligable effect on resolution by incorporating a weighting function, preferentially a Gaussian function, in the image reconstruction.