Studies of a technique for attenuation correction in single photon emission computed tomography

An iterative post-processing technique for attenuation correction in SPECT is presented. A primary uncorrected image is used to estimate the effect of attenuation on measured projection data. The corrected projection data are used in the final reconstruction. The process could be repeated in several iterations but since the results converge very fast only one iteration is needed. The build-up of scattered radiation can be taken into account in the correction procedure. Computer simulations and phantom measurements show that the activity in a transverse section through a source, irrespective of size and position of the source, can be determined with an accuracy of +or-10%. Accurate quantitative evaluation relies on an adequate subtraction of the scattered radiation.