DETERMINING THE DISTRIBUTION OF RADIATION ATTENUATION IN A BODY SECTION

摘要

Using the method and device for computer tomography in accordance with the invention, always fhe same filtering operation can be pertormed for image reconstruction, regardless of the method used to measure the measurement data: parallel (whether equidistant or not) or divergent (whether equiangular or not), provided that before and after the filtering of the measurement data there is performed a multiplication by a pre-conditioning factor and a post-conditioning factor, respectively. The pre-conditioning and post-conditioning factors are dependent on the type of reconstruction and on the position of a measurement data value in the group of measurement data filtered or to be filtered. The fact that the same filter can be used is important notably for computer tomography apparatus in which the (convolution) filter is embodied in an electronic circuit (by means of hardware). The back-projection device of a device in accordance with the invention is suitable for the back-projection of measurement data along either divergent measurement paths or parallel measurement paths for which it requires only the modification of a few constants applied to the back-projection device.