PERFORMANCE COMPARISON OF A STATE-OF-THE-ART NEURO-SPET SCANNER AND ADEDICATED NEURO-PET SCANNER

The state-of-the-art scanners dedicated to functional imaging of the b rain, one a single-photon emission tomography (SPET) scanner and the o ther a positron emission tomography (PET) scanner, have been compared under identical conditions. The aim of the study was to compare the ca pabilities of the devices under conditions resembling the routine clin ical environment, as well as to consider other issues such as radiatio n burden for some common investigations. Both systems have slightly le ss than ll-cm axial fields of view. The PET system can be operated in a septa-less (3D) mode as well as conventionally with septa (2D). The spatial resolution of both devices was less than 8 mm in all dimension s in scattering media. On average, the PET scanner's resolution was ap proximately 10%-15% better than the SPET system. Energy resolution on the SPET system was superior due the scintillator used [NaI(T1)]. Sens itivity in air with a line source on the PET system was found to be si milar to 150 times greater in 3D and similar to 25 times greater in 2D than with the SPET system. A normal subject was studied on each syste m in an attempt to obtain the highest quality data possible for a subj ective comparison. It is clear that, while PET retains the advantages of more desirable radiopharmaceuticals and higher sensitivity, the qua lity obtainable from SPET devices has improved markedly. SPET may prov e as useful for many clinical investigations