Myocardial T1 Mapping: Techniques and Potential Applications

Abstract

Myocardial fibrosis is a common endpoint in a variety of cardiac diseases and a major independent predictor of adverse cardiac outcomes. Short of histopathologic analysis, which is limited by sampling bias, most diagnostic modalities are limited in their depiction of myocardial fibrosis. Cardiac magnetic resonance (MR) imaging has the advantage of providing detailed soft-tissue characterization, and a variety of novel quantification methods have further improved its usefulness. Contrast material-enhanced cardiac MR imaging depends on differences in signal intensity between regions of scarring and adjacent normal myocardium. Diffuse myocardial fibrosis lacks these differences in signal intensity. Measurement of myocardial T1 times (T1 mapping) with gadolinium-enhanced inversion recovery-prepared sequences may depict diffuse myocardial fibrosis and has good correlation with ex vivo fibrosis content. T1 mapping calculates myocardial T1 relaxation times with image-based signal intensities and may be performed with standard cardiac MR imagers and radiologic workstations. Myocardium with diffuse fibrosis has greater retention of contrast material, resulting in T1 times that are shorter than those in normal myocardium. Early studies have suggested that diffuse myocardial fibrosis may be distinguished from normal myocardium with T1 mapping. Large multicenter studies are needed to define the role of T1 mapping in developing prognoses and therapeutic assessments. However, given its strengths as a noninvasive method for direct quantification of myocardial fibrosis, T1 mapping may eventually play an important role in the management of cardiac disease.

Prognostic Relevance of Nonsustained Ventricular Tachycardia in Patients with Pulmonary Hypertension

“…Theoretical and experimental studies identified reduced repolarization reserve, increased myocardial fibrosis, and elevated cytosolic Ca levels that promote EADs as mechanisms triggering tachyarrhythmias [23–28]. Cardiac MRI revealing delayed contrast enhancement [29, 30] and newly technical innovations like myocardial T1 mapping [31] might be helpful in identifying patients with cardiac fibrosis.…”

Determinants of future cardiovascular health in women with a history of preeclampsia

“…However, CMR can be used to identify macroscopic fibrosis with late gadolinium enhancement, and evaluate early (preclinical) myocardial fibrosis with so-called T1 mapping. [83,84] In addition, CMR may be used as an alternative technique to evaluate aortic stiffness, which is strongly related to systolic hypertension and is associated with future cardiovascular events. [85,86] Although sensitivity of CMR is high, the specificity is moderate for detecting major coronary artery lesions, and the availability and costs of CMR equipment currently limit large-scale use.…”

Noninvasive Multimodality Imaging in ARVD/C

“…In subjects with diffuse fibrosis, these differences in signal intensity are lacking, thus resulting in false-negative results. Over the last decade, measurement of myocardial T1 relaxation times (T1 mapping) with gadolinium-enhanced inversion recovery sequences has emerged as a novel approach for quantification of myocardial fibrosis (65). To the best of our knowledge, there have been no reports on T1 mapping in ARVD/C in published reports.…”