A comparison of performance of three gamma camera systems for positron emission tomography

The development of coincidence positron imaging using a gamma camera should significantly increase PET utilization. This study has compared the perfor mance of three such systems with each other and with an equivalent single p hoton emission computed tomography (SPECT) measurement. A Carlson phantom, which consisted of a 20 cm diameter cylinder containing areas of uniform ac tivity, hot lesions, cold lesions and orthogonal alternate hot and cold lin es, was filled with an activity of F-18 chosen to try and best exploit each camera and imaged for a fixed time (27 min). The image quality of 9 mm thi ck slices in each section of the phantom was compared visually. Several ima ge quality parameters were also compared including line source resolution a nd noise equivalent count rate. There were considerable differences in PET image quality between the three cameras hut all were at least as good as th e SPECT image. The full width at half maximum (FWHM) resolution of all syst ems was similar (approximately 4.5 mm) but the maximum noise equivalent cou nt rates in a 20 cm cylinder were significantly different (6.3, 2.6 and 1.6 kcps) (where cps is counts per second) and correlated with the phantom ima ge quality. ((C) 2000 Lippincott Williams & Wilkins).