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Updated: Jun 25, 2026
MRI and PET in Mouse Models of Myocardial Infarction
Published on: December 19, 2013
Accurate and objective infarct sizing by contrast-enhanced magnetic resonance imaging in a canine myocardial
Luciano C Amado1, Bernhard L Gerber, Sandeep N Gupta
1Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 2187, USA.
Objectives:
To identify an accurate and reproducible method to define myocardial infarct (MI) size, we conducted a study in a closed-chest canine model of acute myocardial infarction, in which MI size was measured using different thresholding techniques and by imaging at different delay times after contrast administration.
Background:
The MI size by contrast-enhanced magnetic resonance imaging (CE-MRI) is directly related to long-term prognosis. However, previous measurements were done using nonuniform methods and tended to overestimate nonviable areas.
Methods:
Thirteen animals underwent 90 min of coronary artery occlusion, followed by reperfusion. The CE-MRI data were acquired within 24 h after reperfusion and compared with triphenyltetrazolium chloride pathology. In the first nine animals, images were obtained approximately 15 min after gadolinium diethylene triamine penta-acetic acid (Gd-DTPA) using an inversion-recovery gradient-echo pulse sequence. To identify the most accurate method, MI size by CE-MRI was measured visually and by semi-automatic thresholding techniques, using different criteria. In four additional animals, images were acquired every 6 min until 30 min after Gd-DTPA.
Results:
Postmortem MI size was 13.5 +/- 2.6% of left ventricular volume. Semi-automatic techniques, using full-width at half-maximum (FWHM) criterion, correlated best with postmortem data (r(2) = 0.94, p < 0.001; results confirmed by Bland-Altman plots). Using FWHM, there was no difference in MI size between different delay times after contrast (15.2 +/- 2.9% to 14.5 +/- 4.2% at 6 and 30 min, respectively; p = NS).
Conclusions:
When an objective technique is used to define MI size by CE-MRI, accurate infarct size measurements can be obtained from images obtained up to 30 min after contrast administration.
