Imaging arterial and venous vessels using Iron Dextran enhanced multi-echo 3D gradient echo MRI at 7T

Area of Science:

• Biomedical Imaging
• Radiology
• Neuroimaging

Background:

• Iron dextran, an iron oxide compound, is clinically used for iron-deficiency anemia.
• It exhibits T2 and T2* shortening effects, enabling off-label use as an intravascular MRI contrast agent.
• Susceptibility Weighted Imaging (SWI) is sensitive to magnetic susceptibility differences, useful for blood imaging.

Purpose of the Study:

• To evaluate the feasibility of Iron Dextran-enhanced multi-echo SWI at 7T for human brain arterial and venous imaging.
• To assess the visualization capabilities of this technique for small blood vessels.

Main Methods:

• Phantom experiments were conducted to determine Iron Dextran's r2* relaxivity in blood.
• SWI sequence parameters were optimized based on phantom results.
• Pre- and post-contrast 7T MRI scans were acquired in human subjects, followed by artery and vein mapping.

Main Results:

• Post-contrast SWI images demonstrated an increased susceptibility difference between blood and surrounding tissues in both arteries and veins.
• The Iron Dextran-enhanced SWI approach successfully visualized blood vessels with diameters as small as approximately 100 μm.
• Small blood vessels supplying and draining structures like the hippocampus were clearly depicted.

Conclusions:

• Iron Dextran can serve as an effective iron-based MRI contrast agent for brain blood vessel imaging.
• The proposed Iron Dextran-enhanced multi-echo SWI method provides high-resolution visualization of cerebral vasculature.
• This technique offers a promising alternative for detailed neurovascular imaging.