Characterization of Benign Myocarditis Using Quantitative Delayed-Enhancement Imaging Based on Molli T1 Mapping

Area of Science:

• Cardiovascular Imaging
• Radiology
• Biomedical Engineering

Background:

• Delayed contrast enhancement (DCE) using gadolinium-chelate (Gd-chelate) is crucial for detecting myocardial tissue changes.
• Localization of DCE within the myocardial wall aids in differentiating conditions like myocardial infarction (MI), myocarditis, and cardiomyopathies.

Purpose of the Study:

• To characterize benign myocarditis using quantitative DCE imaging.
• To investigate if extracellular volume fraction (ECV) can differentiate between MI and myocarditis.

Main Methods:

• Utilized Modified Look-Locker Imaging (MOLLI) sequence at 3 Tesla on 6 myocarditis and 18 MI patients.
• Measured myocardial T1 values before and after Gd-chelate injection, normalizing to blood T1 to calculate ECV.
• Compared T1 values and ECV in late gadolinium enhancement (LGE) and normal myocardial regions.

Main Results:

• Both myocarditis and MI showed lower T1 values in LGE regions compared to normal myocardium.
• Myocarditis LGE areas had significantly higher T1 values (446.8±45.8 ms) than MI (360.5±66.9 ms).
• ECV was significantly lower in myocarditis (34.5±3.3%) compared to MI (53.8±13.0%).

Conclusions:

• Quantitative T1 and ECV measurements effectively differentiate between the distinct histological patterns of myocarditis and MI.
• These imaging parameters can distinguish inflammatory (myocarditis) from fibrotic (MI) myocardial tissue changes.
• Further research may refine the predictive risk assessment of LGE severity in myocarditis using ECV changes.