Design Considerations for a Positron Emission Transverse Tomograph (PETT V) for Imaging of the Brain

Abstract

Imaging of the brain by positron emission tomography can be optimized for sensitivity by dedicating the design of the tomograph to this application. A multislice positron emission tomograph (PETT V) was designed for imaging the human brain and the whole body of small experimental animals rhesus monkey''s and dogs. The detector system of PETT V consists of a circular array of 48 NaI(Tl) scintillation detectors, each fitted with 2 photomultiplier tubes, with 1 dimensional positioning capability. Suitable sampling is achieved by rotation of the circular array of detectors and by a wobbling motion of the detector circle. The proposed system is capable of providing 7 slices simultaneously with a spatial resolution in the plane of the slice from 7-15 mm and with slice thicknesses of 7 and 14 mm. The minimum scanning time is 1 s. The estimated overall sensitivity of PETT V is 350,000 counts/s per mCi in a 20 cm diameter phantom for a resolution of approximately 1.5 .times. 1.5 cm. The system is under construction.