Super High Contrast USPIO-Enhanced Cerebrovascular Angiography Using Ultrashort Time-to-Echo MRI

Area of Science:

• Radiology
• Medical Imaging
• Biomedical Engineering

Background:

• Ferumoxytol is an off-label MR contrast agent with good relaxivity and safety.
• Its T2* relaxivity limits T1-weighted positive contrast and causes artifacts in standard MRI.
• Optimized protocols are needed to fully utilize ferumoxytol's potential.

Purpose of the Study:

• To evaluate the first-in-human clinical performance of Quantitative Ultrashort Time-to-Echo Contrast Enhanced (QUTE-CE) MRA.
• To assess ferumoxytol's efficacy as an MRI contrast agent for head/brain vascular imaging using QUTE-CE MRA.
• To compare QUTE-CE MRA with standard MRI techniques.

Main Methods:

• 15 subjects underwent 3.0T MRI using QUTE-CE MRA with ferumoxytol.
• A stack-of-spirals 3D Ultrashort Time-to-Echo sequence was employed.
• Comparisons included time-of-flight MRA, standard T1w imaging, and retrospective gadolinium-enhanced data.

Main Results:

• QUTE-CE MRA showed significantly higher SNR (1707 ± 226) and CNR (1447 ± 189) compared to ferumoxytol T1w and TOF MRA.
• Intraluminal signal heterogeneity (ISH) was significantly lower with QUTE-CE MRA (0.091 ± 0.031).
• Higher CNR improved depth of vessel visualization with reduced heterogeneity.

Conclusions:

• QUTE-CE MRA offers approximately 5-fold superior contrast compared to other enhanced and noncontrast MRA techniques.
• The method demonstrates fewer artifacts and improved vessel visualization.
• This technique holds promise for clinical vascular imaging.