A Linear Whole-Body Scanner for Quantitative Positron Imaging

A linear non-tomographic multicrystal scanner for quantitative positron imaging has been designed. The stationary detector system consists of 64 coincidence detector pairs that are arranged in two opposing detector banks. NaI-crystals of 1.5¿ diameter and 3¿ length are used. The patient bed moves linearly between the transverse detector banks. The scanning area is 64 cm wide and up to 192 cm long. The longitudinal and lateral sampling distances are 1 cm. The spatial resolution of the instrument is 2 cm. The plane sensitivity amounts to 6400 cps for a pure positron emitter of 1 ¿Ci/cm2. The system is controlled by a micro processor (DEC LSI-11). Absolute activities can be calculated by mathematical comparison of consecutive emission and transmission scans. The positron scanner is used for dosimetric and slow metabolic studies in the total body as well as in individual organs. The design of the scanner is discussed. Initial experimental and clinical results are presented.