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Updated: Nov 21, 2025
MRI and PET in Mouse Models of Myocardial Infarction
Published on: December 19, 2013
Tracking the progress of inflammation with PET/MRI in a canine model of myocardial infarction
B Wilk1,2,3, H Smailovic4,5, G Wisenberg4,6
1Lawson Health Research Institute, London, Canada. bwilk@uwo.ca.
Background:
Following myocardial infarction, tissue undergoes pathophysiological changes involving inflammation and scar tissue formation. However, little is known about the pathophysiology and prognostic significance of any corresponding changes in remote myocardium. The aim of this study was to investigate the potential application of a combined constant infusion of 18F-FDG and Gd-DTPA to quantitate inflammation and extracellular volume (ECV) from 3 to 40 days after myocardial infarction.
Methods:
Eight canine subjects were imaged at multiple time points following induction of an MI with a 60-minute concurrent constant infusion of Gd-DTPA and 18F-FDG using a hybrid PET/MRI scanner.
Results:
There was a significant increase in ECV in remote myocardium on day 14 post-MI (P = .034) and day 21 (P = .021) compared to the baseline. ECV was significantly elevated in the infarcted myocardium compared to remote myocardium at all time points post-MI (days 3, 7, 14, 21, and 40) (P < .001) while glucose uptake was also increased within the infarct on days 3, 7, 14, and 21 but not 40.
Conclusions:
The significant increase in ECV in remote tissue may be due to an ongoing inflammatory process in the early weeks post-infarct.
Insights
Following myocardial infarction (MI), remote heart tissue shows increased extracellular volume (ECV), suggesting inflammation. This study quantifies these changes using novel imaging techniques in canines.
Area of Science:
- Cardiovascular Imaging
- Myocardial Pathophysiology
- Nuclear Medicine
Background:
- Myocardial infarction (MI) causes significant changes in heart tissue, including inflammation and scarring.
- The pathophysiology and prognostic implications of changes in remote myocardium post-MI are not well understood.
- Investigating remote myocardial changes is crucial for understanding the overall impact of MI.
Purpose of the Study:
- To evaluate the combined use of 18F-FDG and Gd-DTPA for quantifying inflammation and extracellular volume (ECV) in remote myocardium after MI.
- To assess the temporal changes in ECV and inflammation in remote myocardium from 3 to 40 days post-MI.
- To explore the potential link between increased ECV in remote myocardium and inflammatory processes.
Main Methods:
- Eight canine subjects underwent hybrid PET/MRI scans.
- A constant infusion of Gd-DTPA and 18F-FDG was administered concurrently for 60 minutes.
- Imaging was performed at multiple time points (3-40 days) following induced myocardial infarction.
Main Results:
- Extracellular volume (ECV) in remote myocardium significantly increased on days 14 and 21 post-MI compared to baseline.
- Infarcted myocardium showed significantly elevated ECV compared to remote myocardium at all time points (3-40 days post-MI).
- Increased glucose uptake was observed in the infarct on days 3, 7, 14, and 21, but not on day 40.
Conclusions:
- The observed increase in ECV in remote myocardium suggests an ongoing inflammatory process in the early weeks after myocardial infarction.
- Combined 18F-FDG and Gd-DTPA PET/MRI can quantify changes in remote myocardium post-MI.
- These findings highlight the importance of assessing remote myocardial changes in the context of MI recovery and prognosis.
