Positron emission tomography: instrumentation perspectives

Current trends in positron tomography are toward instrumentation which will provide resolution finer than 7 mm FWHM and a sensitivity of 75,000 events per second, per transverse section, for 1 μCi per cm3 of activity in a 20 cm diameter phantom. Multiple stationary layers of tightly packed crystals with widths of 6 mm or less in circular arrays can provide adequate sampling for thorax or heat PET devices. The major instrumentation problem is to achieve efficient optical coupling between crystals and photo detectors without a sacrifice of sensitivity. Sampling and coupling schemes, an analysis of the time-of-flight gains and aspects of data acquisition and display are presented