T2 mapping in myocardial disease: a comprehensive review

Abstract

Cardiovascular magnetic resonance (CMR) is considered the gold standard imaging modality for myocardial tissue characterization. Elevated transverse relaxation time (T2) is specific for increased myocardial water content, increased free water, and is used as an index of myocardial edema. The strengths of quantitative T2 mapping lie in the accurate characterization of myocardial edema, and the early detection of reversible myocardial disease without the use of contrast agents or ionizing radiation. Quantitative T2 mapping overcomes the limitations of T2-weighted imaging for reliable assessment of diffuse myocardial edema and can be used to diagnose, stage, and monitor myocardial injury. Strong evidence supports the clinical use of T2 mapping in acute myocardial infarction, myocarditis, heart transplant rejection, and dilated cardiomyopathy. Accumulating data support the utility of T2 mapping for the assessment of other cardiomyopathies, rheumatologic conditions with cardiac involvement, and monitoring for cancer therapy-related cardiac injury. Importantly, elevated T2 relaxation time may be the first sign of myocardial injury in many diseases and oftentimes precedes symptoms, changes in ejection fraction, and irreversible myocardial remodeling. This comprehensive review discusses the technical considerations and clinical roles of myocardial T2 mapping with an emphasis on expanding the impact of this unique, noninvasive tissue parameter.

Impact of Sex and Cardiovascular Risk Factors on Myocardial T1, Extracellular Volume Fraction, and T2 at 3 Tesla: Results From the Population-Based, Hamburg City Health Study

“…17 The effect of heart rate on T2 could be explained by the introduction of T1 effects at higher heart rates. 49 Nevertheless, this study provides interindividual findings in a large population but is not suited to assess intraindividual, technical/sequence specific effects of heart rate on measured myocardial T2 values. Finally, individuals with cardiovascular risk factors had significantly lower median T2 values compared with individuals without any cardiovascular risk factor (Table 2).…”

“…1 Of note, it is important to consider in this context that an abnormal biomarker above the reference limit such as myocardial T1, ECV, and T2 is not necessarily equivalent with the presence of disease. 49…”

Heart Failure and Cardiomyopathies: CT and MR from Basics to Advanced Imaging

“…T2 imaging and, in particular, T2 mapping are valuable tools for the quantification of water content. Although high T2 values cannot discriminate between inflammatory and non-inflammatory edema, T2 is helpful in defining acute myocardial injury, more aggressive storage disease and congestive water accumulation in advanced HF [ 114 , 115 ].…”

Certainties and Uncertainties of Cardiac Magnetic Resonance Imaging in Athletes

“…Native T1 mapping enables the quantitative assessment of tissue characteristics such as myocardial fibrosis [ 63 ], amyloid deposition [ 64 ] and lipid accumulation [ 65 ]. T2 mapping can detect myocardial edema in various settings including acute myocarditis [ 66 ]. Therefore, non-contrast mapping techniques might have an impact on the early detection of diffuse pathologies while maintaining a relatively short scan time and without the addition of contrast material.…”