Quantitative myocardial distribution volume from dynamic contrast-enhanced MRI.

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Biomedical Engineering

Background:

• The extracellular volume (v(e)) represents the extravascular space in myocardial tissue.
• Elevated v(e) in infarcted regions indicates a loss of viable cardiac cells.
• Quantitative v(e) estimation offers complementary information to delayed enhancement MRI.

Purpose of the Study:

• To investigate the utility of dynamic contrast-enhanced MRI (DCE-MRI) for quantifying myocardial v(e).
• To assess v(e) in both normal and infarcted myocardial regions.
• To evaluate the accuracy and time efficiency of DCE-MRI for v(e) estimation.

Main Methods:

• Utilized a hybrid gradient echo-echoplanar imaging sequence on a 1.5T MRI scanner.
• Imaged 12 normal subjects and 4 infarct patients dynamically during contrast agent injection.
• Employed compartment modeling to fit blood and tissue enhancement curves for v(e) estimation.

Main Results:

• Aggregate v(e) estimates were 23.6±6.3% in normal myocardium and 45.7±3.4% in infarct regions.
• DCE-MRI results showed no significant difference compared to reference standards (Ct/Cb).
• v(e) estimation required approximately 1 minute for normal myocardium and up to 3 minutes for infarct regions.

Conclusions:

• DCE-MRI can accurately quantify myocardial v(e) in normal and infarcted tissues.
• The method provides quantitative spatial distribution of v(e), aiding in infarct assessment.
• Compartment modeling of DCE-MRI data allows for v(e) estimation, offering valuable clinical insights.