METHOD FOR AUTOMATIC CENTERING OF AN OBJECT TO BE EXAMINED IN A FAN BEAM TOMODENSITOMETER AND TOMODENSITOMETER SUITABLE FOR THIS METHOD

摘要

P Tomodensitometer developing the image of a section of an object using the results of a computer calculation of the signals emitted by a line of detectors arranged in a fan opposite an X-ray source. In the centering position a program is sent to the computer so that it can work out the direction and the length by which the object to be examined must be moved so that it is inside the measurement field. To reduce or cancel the dose of radiation received during the centering cycle, a screen placed between the source and the body to be examined obscures the rays except those which must strike the end detectors. /P P Application to general purpose CT scanners. /P