# Development of a High Performance Clinical Cardiac SPECT/TCT System

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 2020 · $732,505

## Abstract

This proposal’s objective is to complete a Single Photon Emission Computed Tomography (SPECT)
system dedicated to human cardiac imaging. It is stationary, in the sense that all views needed for a given
configuration are simultaneously acquired over the Field of View (FOV), yet adaptive in that it can change its
resolution-sensitivity-FOV tradeoff in about 10 seconds without needing to move the patient. To do this, it takes
advantage of the separability of slit-slat collimation, which uses a slit to collimate the transverse direction and a
set of slats to collimate the axial direction, similar to parallel-beam. The slits can be adapted into one of five
view configurations using a high-precision, continuous-loop conveyor that moves different slit plates into
position. The slats are adaptive into two positions using pneumatic actuators that compress adjacent slats into
a single slat, doubling the sensitivity at the cost of resolution. The system also has a transmission source that
allows for attenuation correction so that quantitative dynamic imaging is very realistic, in addition to accurate
patient positioning before dynamic scanning. The prototype system is nearing completion. Adaptation to a
clinical prototype (Aim 1) requires (i) adding a smart chair for positioning and re-positioning the patient so that
different data can be acquired in different configurations (e.g., scout + hi-resolution + transmission); (ii) adding
a cover with touch pads for patient safety; and (iii) completing software integration so that multiple modes (e.g.,
transmission and scout imaging) can be run with proper re-positioning of the patient (e.g., transmission
followed by centering the heart for focal imaging based on online reconstruction). After system testing and
optimization for static imaging (Aim 2) and dynamic imaging (Aim 3), we will then test dynamic cardiac imaging
to quantify myocardial blood flow (MBF) in an animal model, with confirmation through microspheres (Aim 4).
Successfully measuring MBF in patients, something that is commonplace in PET but extraordinary challenging
in SPECT because (i) systems often need to rotate; (ii) quantification is sometime not available (e.g., D-
SPECT); and (iii) the ability to apply appropriate corrections is compromised. For instance, dynamic imaging in
SPECT really requires a high-sensitivity mode to capture the input function and fast dynamics, yet also
requires high-resolution to correct for spill-over – due to limited spatial resolution and cardiac motion. Without
these corrections, one cannot account for the non-linear extraction of the tracer (i.e., the extraction fraction
decreases with increasing blood flow). We hypothesize that the combination of high-sensitivity for dynamic
imaging, combined with high-resolution for quantitative corrects, coupled with both scatter and attenuation
correction, will yield MBF in human patients comparable to that achieved with PET, as tested in Aim 5. We
believe that if this project...

## Key facts

- **NIH application ID:** 10002038
- **Project number:** 5R01HL108119-09
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** SCOTT DEAN METZLER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $732,505
- **Award type:** 5
- **Project period:** 2012-04-06 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10002038

## Citation

> US National Institutes of Health, RePORTER application 10002038, Development of a High Performance Clinical Cardiac SPECT/TCT System (5R01HL108119-09). Retrieved via AI Analytics 2026-06-08 from https://api.ai-analytics.org/grant/nih/10002038. Licensed CC0.

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