# ANALOG CODED SYSTEMS FOR POSITRON TOMOGRAPHY

> **NIH NIH R01** · MASSACHUSETTS GENERAL HOSPITAL · 1989 · $329,554

## Abstract

Positron tomography has reached a critical point in its development.
Numerous studies have shown that this technique can produce useful
information in animal and man that cannot be provided by any other imaging
system.  However, positron imaging has been limited because of relatively
poor resolution.  We have developed powerful techniques of analog coding
which permits the design of high resolution instruments.

PCR-I is an analog coded single ring prototype system for positron
tomography.  The system currently is operating at 4.5mm resolution without
the use of interpolative motion.  Studies are underway using phantoms and
animal systems to study areas of application of this instrument.  This
instrument shows high resolution, high sensitivity, relatively low random
and prompt scatter coincidence rates and excellent stability and linearity.

Based on the design of PCR-I, we propose to develop an analog coded
cylindrical positron tomograph to image volume distributions of positron
emitting activity.  Physical studies will be carried out using Monte Carlo
calculations and experiments to determine the effects of randoms and prompt
scatter coincidences.  Studies will be carried out for different source
geometries and activity levels.  By use of a powerful simulation program,
the design parameters of PCR-II, an analog coded cylindrical positron
tomograph, will be determined.  Again, by use of simulation, the
performance of the instrument will be predicted for different imaging tasks.

PCR-II will provide an instrument with resolution approaching the physical
limitations of positron range and small angle deviation and yielding very
high sensitivity and count rate capability.  The two dimensional analog
coding permits each phototube to identify a large number of detector
elements, thus permitting a design with thousands of detectors.  The system
will also operate without interpolative motion.  Stability and linearity
should be equal to that of PCR-I.

A three dimensional reconstruction algorithm will be used to reconstruct
the source distribution within the volume source.  The problems encountered
in use of this algorithm will be investigated again by simulation.

## Key facts

- **NIH application ID:** 3170748
- **Project number:** 5R01CA032873-09
- **Recipient organization:** MASSACHUSETTS GENERAL HOSPITAL
- **SAM.gov UEI:** FLJ7DQKLL226
- **Principal Investigator:** GORDON L BROWNELL
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $329,554
- **Award type:** 5
- **Project period:** 1981-08-01 → 1991-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3170748

## Citation

> US National Institutes of Health, RePORTER application 3170748, ANALOG CODED SYSTEMS FOR POSITRON TOMOGRAPHY (5R01CA032873-09). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3170748. Licensed CC0.

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