A Contemporary Review of Imaging in Arrhythmogenic Cardiomyopathy.

Arrhythmogenic cardiomyopathy (ACM) is a rare inherited disease characterized by fibrofatty replacement of the myocardium, associated with lethal arrhythmias and heart failure. ACM diagnosis is challenging, as it involves clinical, genetic, and multiparametric imaging assessments. Imaging plays a central role in evaluating ACM by targeting the intertwined morphofunctional and tissue abnormalities. Cardiac MRI is the reference technique due to its ability to depict both types of abnormalities comprehensively and without radiation. Over the past decade, advances in regional deformation analysis and tissue characterization have improved detection of early-stage disease and recognition of left ventricular (LV) involvement, expanding beyond the classic right ventricle phenotype and leading to updated diagnostic criteria. CT, with its superior and isotropic spatial resolution, strong native contrast for adipose tissue, and potential dynamic four-dimensional acquisition, could play a key role in ACM diagnosis and characterization, particularly in patients with implanted devices. This review explores the strengths and limitations of cardiac MRI and CT in ACM evaluation, emphasizing LV involvement and new diagnostic criteria. It also addresses key challenges, such as the prognostic value of cardiac MRI and structural disease progression, while discussing the latest advancements and future directions for both modalities.