# Improved Estimation of Ischemic Burden with Cardiac MRI

> **NIH NIH R01** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 2020 · $381,250

## Abstract

Improved estimation of ischemic burden with cardiac MRI
Summary: Coronary artery disease (CAD) is a major healthcare problem that affects over 20 million Americans
and costs our nation an estimated $82.8 billion each year. Myocardial perfusion imaging is a proven tool to
detect and characterize CAD. Perfusion defect size, also termed ischemic burden, is a promising biomarker not
only for triaging patients for catheterization but also in longitudinal studies to determine the efficacy of therapy
and to predict future cardiac events. While these and most other studies to date used Single Photon Emission
Computed Tomography (SPECT) imaging, Magnetic Resonance Imaging (MRI) may be more suitable for
estimating ischemic burden. MRI offers superior in-plane spatial resolution than SPECT without the ionizing
radiation and in a fraction of the total exam time. MRI also offers a gold standard Late Gadolinium Enhancement
(LGE) imaging method for identifying infarcted myocardial tissue. By subtracting the infarcted tissue size from
the perfusion defect size computed using MR stress perfusion images, a more accurate estimation of ischemic
burden is possible. However, the resolution and slice coverage obtained with standard perfusion MRI is limited
and often involves skipping large regions of myocardial tissue between the slices acquired. The inevitable
tradeoff between having complete slice coverage and preserving high temporal resolution potentially leads to
missed regions of perfusion deficit. The tradeoff problem is exacerbated when the ECG gating signal is poor
and when imaging patients with irregular heart rate, for example in patients with atrial fibrillation, a common
condition in patients with CAD. Ungated cardiac perfusion MRI is a recently popular approach that mitigates this
tradeoff by continuously acquiring data with very high temporal resolution irrespective of the ECG signal. Poor
or inconsistent ECG gating can also affect LGE imaging requiring several additional breath holds and long
acquisition times with conventional segmented acquisitions. Inconsistent R-R interval between the inversion
pulses leads to incomplete recovery of longitudinal magnetization and improper nulling of the healthy tissue in
LGE imaging. Ungated free-breathing acquisitions are also simpler than conventional acquisitions which impose
breath-holding and ECG gating signal requirements. A simpler and more robust protocol can lead to wider
adoption of cardiac MRI techniques for CAD management. Specific aims are (1) To develop novel simultaneous
multi-slice techniques with advanced reconstruction methods that are robust to the motion. (2) To rigorously
compare the new MR methods with existing MR technology. (3) To validate the new framework by comparing
ischemic burden computed using SPECT in a pilot study. Our team has complementary experience to
successfully execute all aspects of this project. The success of our study will deliver a game-changing
technology that addresses ...

## Key facts

- **NIH application ID:** 9931266
- **Project number:** 5R01HL138082-04
- **Recipient organization:** UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH
- **Principal Investigator:** Ganesh Adluru
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $381,250
- **Award type:** 5
- **Project period:** 2017-07-01 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9931266

## Citation

> US National Institutes of Health, RePORTER application 9931266, Improved Estimation of Ischemic Burden with Cardiac MRI (5R01HL138082-04). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/9931266. Licensed CC0.

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