CT and MR imaging of cardiomyopathies in clinical practice -- an approach after an abnormal echocardiogram or electrocardiogram

Cardiomyopathies represent a diverse group of myocardial disorders characterized by structural and functional abnormalities in the absence of significant coronary artery disease or other primary causes. This review highlights the diagnostic and prognostic value of cardiac magnetic resonance and computed tomography in the assessment of cardiomyopathies. While echocardiography remains the first-line imaging modality, CMR and CCT offer superior tissue characterization, morphological assessment, and functional evaluation, crucial for phenotyping cardiomyopathies into hypertrophic, dilated, restrictive, arrhythmogenic, and non-dilated left ventricular subtypes. For hypertrophic cardiomyopathy, CMR enables precise identification of fibrosis, hypertrophy distribution, and risk stratification for sudden cardiac death. CMR is pivotal in identifying phenocopies, like cardiac amyloidosis and Anderson-Fabry disease, and differentiating between pathological and physiological remodeling in athlete's heart. For dilated cardiomyopathy, late gadolinium enhancement, T1 mapping, and extracellular volume measurements aid in distinguishing etiologies and predicting adverse outcomes. In arrhythmogenic right ventricular cardiomyopathy CMR demonstrates superior sensitivity for detecting structural abnormalities in the right ventricle, and the presence of fibrosis, which is associated with arrhythmic risk. CCT main roles are excluding coronary artery disease and complementing CMR. This review proposes a diagnostic pathway integrating multimodality imaging for clinical management in cardiomyopathies.