The Donner 280-Crystal High Resolution Positron Tomograph

We describe a stationary positron tomooraph desiqned for the rapid, accurate, three-dimensional imaging of positron-labeled compounds anywhere in the human body. The system consists of a large gantry containing lead shieldinq and a 92 cm diam ring of 280 closely-packed rectanqular NaI(Tl) crystals, lightpipes and phototubes; coincidence and address circuits; semiconductor histogram memory; a hard-wired reconstructor; and a gray-level CRT. Event rates, backgrounds and resolution test images are presented.