New imaging systems in nuclear medicine. Technical progress report, June 1, 1980-May 31, 1981

Three areas of work are reported: (1) the development of the Analogue Ring Detector; (2) other instrument development; and (3) instrument applications. The analogue ring design calculations and measurements were made for a single slice NaI(Tl) detector PC Ring. Detector material other than NaI was evaluated for the analogue ring design. Design studies for a high resolution detector using BGO were made and a high data rate detector using CsF is being designed. The design concept for PC Ring uses BGO rather than NaI as a detector material. Subsequent studies indicated that it is also the preferred design for NaI(Tl). The design of PC ring is complete to the computer interface. Layout of the electronics boards including preamplifier, position sensing, and coincidence logic is complete. Testing of the partially assembled detector will begin September 1. Initial design studies for a 50 cm diameter, high-resolution BGO analogue ring were made. Monte-Carlo studies of stopping power, spatial resolution, and light spread function were made. Measurements were made with a 4 PM tube section using 3 BGO detector elements and two types of PM tubes. The detector elements were polished and coated with reflective paint. The spatial resolution measured with the RCA S83012E PM tubes was 3.9 mm FWHM for events greater than 400 keV. Preliminary design studies were made for a high data rate CsF analogue ring detector. The goal is for 1 cm resolution using 2.8 cm diameter PM tubes. Measurements using CsF have not yet been made. Summaries of the clinical applications of the positron instrument are included. Applications include CNS, Cardiovascular, and pulmonary imaging studies