Clinical Advances in Extracellular Volume Measurement by Cardiac Computed Tomography and Magnetic Resonance Imaging: Current Status and Future Perspectives

The myocardial extracellular volume (ECV) has emerged as a critical biomarker for diagnosing and managing cardiac disease, as it reflects changes in myocardial tissue composition such as fibrosis and edema. Cardiac magnetic resonance imaging (MRI) and computed tomography (CT) have increasingly been used to non-invasively quantify ECV, providing valuable insights into myocardial pathology. This review summarizes the latest advancements in ECV measurement techniques using cardiac CT and MRI, emphasizing their clinical applications in conditions including cardiomyopathies, myocardial fibrosis, and heart failure. We discuss the technical principles underlying ECV quantification via both imaging modalities, compare their diagnostic accuracy and reproducibility, and highlight the complementary roles they play in clinical practice. Challenges such as standardization, radiation exposure in CT, and contrast agent considerations are also addressed. By analyzing current literature, we provide an overview of the consistency and discrepancies between CT- and MRI-derived ECV measurements, and propose future directions for improving imaging protocols, expanding clinical indications, and integrating ECV assessment into personalized treatment strategies. This comprehensive review aims to inform clinicians and researchers about the evolving role of ECV quantification in cardiac imaging and its potential to enhance cardiovascular disease diagnosis and management.