ANORDNING FOR BESTEMNING AV STRALNINGSABSORPTIONSFORDELNINGEN I ETT UNDERSOKNINGSPLAN

摘要

In computed tomography apparatus the radiation intensity of the radiation source remains constant during a measuring operation. This means that in those positions in which the absorption of the radiation through the patient is particularly weak, the patient gets an unnecessarily large dose without any useful effect, as only a distinct number of X-ray quanta is required for a given measuring accuracy. It is an object of the invention to measure the radiation absorption distribution at a reduced dose but without the measuring accuracy being affected. The radiation intensity of the radiation source in a measuring position is made dependent on the mean measuring error of the adjacent measuring position; the mean measuring error does then indeed not remain constant but it fluctuates less than when a constant intensity of the radiation source is used.