Role of CMR Mapping Techniques in Cardiac Hypertrophic Phenotype

Abstract

Non-ischemic cardiomyopathies represent a heterogeneous group of myocardial diseases potentially leading to heart failure, life-threatening arrhythmias, and eventually death. Myocardial dysfunction is associated with different underlying pathological processes, ultimately inducing changes in morphological appearance. Thus, classification based on presenting morphological phenotypes has been proposed, i.e., dilated, hypertrophic, restrictive, and right ventricular cardiomyopathies. In light of the key diagnostic and prognostic role of morphological and functional features, cardiovascular imaging has emerged as key element in the clinical workflow of suspected cardiomyopathies, and above all, cardiovascular magnetic resonance (CMR) represents the ideal technique to be used: thanks to its physical principles, besides optimal spatial and temporal resolutions, incomparable contrast resolution allows to assess myocardial tissue abnormalities in detail. Traditionally, weighted images and late enhancement images after gadolinium-based contrast agent administration have been used to perform tissue characterization, but in the last decade quantitative assessment of pre-contrast longitudinal relaxation time (native T1), post-contrast longitudinal relaxation time (post-contrast T1) and transversal relaxation time (T2), all displayed with dedicated pixel-wise color-coded maps (mapping), has contributed to give precious knowledge insight, with positive influence of diagnostic accuracy and prognosis assessment, mostly in the setting of the hypertrophic phenotype. This review aims to describe the available evidence of the role of mapping techniques in the assessment of hypertrophic phenotype, and to suggest their integration in the routine CMR evaluation of newly diagnosed cardiomyopathies with increased wall thickness.

Cardiac Imaging in Athlete’s Heart: The Role of the Radiologist

“…T2 mapping technique is mainly used to identify and quantify myocardial edema in different cardiac diseases including myocarditis, myocardial infarction, sarcoidosis, and amyloidosis [ 16 ].…”

“…In each slice, three T2-weighted images are obtained with different T2 preparation times, usually at 0 ms, 25 ms, and 55 ms. Then, the images are processed applying a motion correction algorithm to reduce respiratory and cardiac motion artifacts. Finally, the T2 mapping images are generated [ 16 ].…”

“…T2 mapping has several advantages compared to T2-weighted spin-echo inversion recovery sequences, traditionally used to evaluate myocardial edema, which are often of limited value due to susceptibility or slow-motion artefacts. Moreover, T2 mapping allows the quantification of edema [ 16 ].…”

“…In the absence of iron overload, T2 mapping values increase only with edema. With iron overload or myocardial hemorrhage T2 mapping values decrease [ 16 ].…”

Bolus Intravenous Procainamide in Patients with Frequent Ventricular Ectopics during Cardiac Magnetic Resonance Scanning: A Way to Ensure High Quality Imaging

“…Cardiac magnetic resonance (CMR) provides excellent assessment of cardiac morphology and function and enables detailed myocardial tissue characterization with a high degree of precision [ 1 ]. Using the late gadolinium enhancement technique for regional myocardial scar detection as well as novel T1 mapping techniques for diffuse fibrosis assessment, CMR is widely regarded as the gold standard for identifying structural arrhythmogenic substrate in patients with ventricular arrhythmias, which is often not detected in conventional investigations [ 2 , 3 ].…”