Review of Multimodality Imaging in Hypertrophic Cardiomyopathy: Diagnosis, Risk Stratification, and Therapeutic Guidance.

Hypertrophic cardiomyopathy (HCM) requires multimodality imaging for accurate diagnosis, risk assessment, and management strategies. Echocardiography serves as the primary imaging tool, evaluating left ventricular wall thickness, outflow tract gradients, and mitral valve morphology. It provides essential diagnostic information and guides treatment decisions, with stress echocardiography particularly valuable for detecting dynamic gradients in obstructive HCM and supporting preoperative planning for interventions such as myectomy. Cardiovascular MRI complements echocardiography through superior resolution, enabling detailed assessment of myocardial mass, flow dynamics, and comprehensive tissue characterization. Late gadolinium enhancement and extracellular volume measurements enhance prognostic evaluation and risk stratification. Cardiac MRI excels at helping distinguish HCM from phenocopies like infiltrative or storage diseases and detecting myocardial disarray, microvascular dysfunction, and abnormalities in myocardial metabolism. Nuclear imaging proves crucial for identifying HCM phenocopies, including transthyretin amyloidosis and sarcoidosis, providing specific diagnostic capabilities. Cardiac CT, while having a secondary diagnostic role, becomes invaluable for evaluating coronary anatomy in patients considered for septal reduction therapies, ensuring comprehensive preoperative assessment. This integrated multimodal approach provides comprehensive HCM evaluation, enabling precise diagnosis, robust risk stratification, and individualized treatment planning. Each modality contributes unique strengths that collectively enhance clinical decision-making and optimize patient outcomes in this complex myocardial disease. Keywords: Cardiomyopathies, Applications-Multimodal, CT, Echocardiography, MR Imaging, SPECT, SPECT/CT, Cardiac Supplemental material is available for this article. © RSNA, 2025.