Subtraction of Compton-scattered photons in single-photon emission computerized tomography.

A technique for scatter correction in single photon emission computerized tomography (SPECT) is described. The method is based on "deconvolution" of scattered events from the measured profile data. The function defining the scatter distribution was determined from measurements with a line source in circular and rectangular water phantoms. The accuracy of the method was tested on a simple phantom simulating a SPECT investigation of the liver. The indicated ratio of the activity concentration in a photon-deficient area, 60 mm diameter in the "liver", relative to its surroundings, was 0.28/1 without scatter correction and 0.01/1 with the correction.