post-contrast T1
T1 relaxation time measurement obtained after gadolinium administration, used to calculate extracellular volume fraction and assess myocardial fibrosis.
Full Definition
Post-contrast T1 refers to the T1 relaxation time of myocardial tissue measured following gadolinium-based contrast agent administration. The contrast agent distributes in the extracellular space, shortening T1 relaxation times proportional to its concentration. When combined with native T1 measurements and hematocrit values, post-contrast T1 enables calculation of the extracellular volume fraction (ECV), which quantifies the proportion of myocardial tissue occupied by extracellular matrix. This parameter is particularly valuable for detecting and monitoring diffuse myocardial fibrosis in various cardiomyopathies, where conventional late gadolinium enhancement may appear normal despite significant pathologic changes.
Usage
Usage note: Specify timing after contrast administration; always report units in milliseconds.
In Context
- "Post-contrast T1 values were significantly shortened to 450 ms, enabling accurate ECV calculation." — Quantitative cardiac MRI analysis
- "The protocol acquires post-contrast T1 maps at 15 minutes following gadolinium injection." — MRI acquisition protocol