# IN VIVO RADIONUCLIDE QUANTITATION USING EMISSION CT

> **NIH NIH R01** · DUKE UNIVERSITY · 1991 · $267,791

## Abstract

Quantitative single photon emission compute tomography (SPECT) has been
limited mainly by the inadequate number of detected photons in the
projections, attenuation within the body, the inclusion of scattered
photons in the projections, and variations in collimator response with
distance.  The long term objectives of this project are:  1) to increase
the number of detected photons by using new acquisition geometries, and 2)
to develop and evaluate a unified reconstruction methodology for SPECT
using a statistical Bayesian formulation.  Cone beam collimation (CB) can
result in a three-fold increase in the number of detected photons, compared
with a parallel beam (PB) collimator having similar resolution
characteristics.  Bayesian image processing (BIP) can integrally include
the a priori source distribution entropy information, the Poisson nature of
the measured projection data, as well as other a priori information
concerning the shift-variant point spread function.  Filtered
backprojection (FBP) is widely used since it offers the practical advantage
of fast computational speed; however, BIP offers the potential for a more
accurate reconstruction.  Other statistical estimators, such as maximum
likelihood (ML) and maximum entropy (MAXENT) are directly derivable from
the Bayesian formulation.  This project will evaluate cone beam SPECT using
FBP and BIP approaches.  A validated Monte Carlo model of the acquisition
geometry will be used to determine the system response matrix.  Receiver
operator characteristic (ROC) curves will be used to evaluate lesion
detectability for CB, fan beam (FB), and PB SPECT.  The convergence
characteristics of BIP will be quantitatively compared with ML and MAXENT,
as a function of iteration number.  Simulated and experimentally acquired
projections of phantoms will be used to evaluate BIP for quantification of
activity, activity ratios, resolution, and noise cone beam SPECT.  Patient
scans acquired with CB, FB, and parallel hole collimation will be compared.

Early results indicate that cone beam collimation offers the potential for
improved SPECT imaging.  The application of a unified BIP algorithm that
simultaneously compensates for attenuation, scatter, and collimator
variations should offer further improvements in the accuracy of the
reconstruction, and provide the basis for fundamental advances in SPECT
quantification.

## Key facts

- **NIH application ID:** 3171393
- **Project number:** 5R01CA033541-09
- **Recipient organization:** DUKE UNIVERSITY
- **SAM.gov UEI:** TP7EK8DZV6N5
- **Principal Investigator:** RONALD J JASZCZAK
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $267,791
- **Award type:** 5
- **Project period:** 1983-03-01 → 1994-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3171393

## Citation

> US National Institutes of Health, RePORTER application 3171393, IN VIVO RADIONUCLIDE QUANTITATION USING EMISSION CT (5R01CA033541-09). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3171393. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*