Double Inversion Recovery MRI with fat suppression at 7 tesla: initial experience

Area of Science:

• Medical Imaging
• Neuroimaging
• Magnetic Resonance Imaging

Background:

• Double Inversion Recovery (DIR) Magnetic Resonance Imaging (MRI) suppresses signals from tissues with different T1 relaxation times.
• DIR-MRI is used in the brain to image gray matter (GM) by nulling white matter (WM) and cerebrospinal fluid (CSF) signals.
• Low signal-to-noise ratio (SNR) is a limitation of DIR, but high-field 7 Tesla (7T) magnets offer potential for higher SNR.

Purpose of the Study:

• To demonstrate the feasibility of in vivo brain Double Inversion Recovery Magnetic Resonance Imaging (DIR-MRI) at 7 Tesla.
• To evaluate fat suppression techniques for DIR-MRI at 7T and 3T.

Main Methods:

• MRI experiments were conducted on phantoms and four healthy volunteers at 7T and 3T.
• A chemical shift selective Fat Inversion Recovery (csFatIR) technique was used for fat suppression and compared to standard fat saturation (FatSat).

Main Results:

• The csFatIR method demonstrated significantly higher efficiency than FatSat at 7T.
• csFatIR was also slightly more efficient than FatSat at 3T.
• Both methods enabled clear delineation of gray matter.

Conclusions:

• Double Inversion Recovery (DIR) Magnetic Resonance Imaging (MRI) is feasible at 7 Tesla for in vivo brain imaging.
• DIR-MRI at 7T is achievable despite challenges with B1 in-homogeneity.
• The study highlights the potential of 7T MRI for improved neuroimaging.