Cardiac MRI with T2 Testing for Myocardial Inflammation Diagnosis

Introduction to Cardiac MRI with T2 Testing

The American College of Cardiology recommends cardiac MRI with T2 testing as a non-invasive imaging technique for evaluating myocardial inflammation by detecting tissue edema, a key component of acute inflammatory processes in the heart 1, 2
Cardiac MRI provides detailed structural and functional assessment of the heart without radiation exposure, and T2 testing measures or visualizes T2 relaxation times in cardiac tissue, sensitive to increased water content (edema) in the myocardium 1, 2

T2 testing is used to detect myocardial edema, a hallmark of acute myocarditis, acute myocardial inflammation in cardiomyopathies, and active cardiac sarcoidosis, with T2 abnormalities helping to differentiate between acute and chronic myocardial injury 1, 4, 5
The American College of Cardiology's 2018 updated Lake Louise Criteria state that CMR provides strong evidence for acute myocardial inflammation when both a T2-based marker for myocardial edema and a T1-based marker for associated myocardial injury are present 1, 2

T2-based markers, such as T2-weighted imaging and T2 mapping, specifically detect edema, with T2-weighted imaging using specialized sequences and T2 mapping directly measuring T2 relaxation times 1, 2, 3, 4
T2 mapping has advantages over traditional T2-weighted imaging, including higher signal-to-noise ratio, shorter breath-holds, direct quantification of T2 values, improved intraobserver and interobserver variability, and better diagnostic confidence 4, 8, 6

During inflammation, increased vascular permeability, endothelial cell contraction, vasodilation, and net expansion of the extracellular space lead to increased myocardial water content (edema), prolonging T2 relaxation time 7

T2 mapping is useful for ruling out active inflammation, with a sensitivity of 89%, and T2 abnormalities may be reversible with treatment, as demonstrated in cardiac sarcoidosis 4, 8, 6
T2 elevations are most pronounced during early, acute inflammation and diminish as inflammation subsides, with T2 mapping potentially more specific for acute inflammation compared to T1 mapping 8, 6