extracellular volume fraction
Quantitative CMR parameter measuring the proportion of extracellular space in myocardium, used to detect diffuse fibrosis.
Full Definition
Extracellular volume fraction (ECV) is a quantitative cardiac MRI biomarker that measures the percentage of myocardial tissue volume occupied by extracellular space. ECV is calculated using pre- and post-contrast T1 mapping combined with hematocrit measurement, providing a non-invasive assessment of diffuse myocardial fibrosis. Normal ECV values range from 20-30%, while elevated values (> 30%) indicate increased extracellular space due to fibrosis, edema, or infiltration. ECV is particularly valuable in cardiomyopathies, cardiac amyloidosis, and monitoring cardiotoxicity where diffuse rather than focal changes predominate.
Usage
Usage note: Report ECV as percentage; normal range 20-30%. Requires hematocrit measurement.
In Context
- "Extracellular volume fraction was elevated at 45%, consistent with cardiac amyloidosis." — CMR report for amyloid assessment
- "ECV mapping revealed diffuse fibrosis with values of 35% throughout the left ventricular myocardium." — Cardiomyopathy evaluation