Scatter suppression by using a rotating pin source in PET transmission measurements

Abstract

Transmission scans used essentially for attenuation correction in whole-body studies with positron-emission tomography (PET) contain different amounts of scatter contamination, depending on the source used. It is shown by phantom studies that scatter causes spatial distortions and nonuniformities in the attenuation images, leading to errors in the attenuation correction factors. For these measurements a ring-shaped transmission source is simulated by a 6-cm-long rotating pin source containing 5 mCi of /sup 68/Ge. The measurements are performed using large phantoms filled with water. Scattered radiation is substantially suppressed by selecting only chords through the actual position of the source instead of collecting all coincident events. Improved edge delineation and homogeneity of the attenuation images are achieved.<>