Performance of a GSO Brain PET Camera

A high sensitivity, high resolution brain PET scanner has been developed. The scanner comprises 58 rows of 320 4 x 4 x I O mm3 gadolinium orthosilicate (GSO) crystals, coupled to a continuous light guide that is sampled by 288 39-mm photomultiplier tubes in a hexagonal grid. A distortion removal algorithm has been developed to remove position non-linearities and to identify individual crystal regions in a flood image with physical crystal locations on the scanner. A central profile through a sinogram of a point source in the center of the scanner shows that the spatial resolution (fwhm) is 3.5 mm (fwtm=8.4 mm). The Hoffman brain phantom has been successfully imaged to demonstrate the capability of the scanner. Table 1 Comparison of physical properties of NaI(TI), LSO and GSO scintillators. The decay time given for GSO corresponds to a Cerium concentration of 0.5% moles.