Simultaneous fat saturation and magnetization transfer contrast imaging with steady-state incoherent sequences

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Pulse Sequence Design
• Biomedical Engineering

Background:

• Steady-state incoherent (SSI) pulse sequences are widely used in MRI.
• Simultaneous fat suppression and magnetization transfer (MT) contrast are desirable for enhanced image quality.
• Existing methods may struggle with magnetic field inhomogeneity.

Purpose of the Study:

• To develop and validate a combined radiofrequency (RF) pulse for simultaneous fat suppression and MT contrast.
• To integrate this pulse with SSI sequences for B0-insensitive fat suppression.
• To introduce an adapted RF spoiling scheme for improved performance.

Main Methods:

• Development of a novel n-dimensional fat saturation (fat sat) and MT contrast RF pulse.
• Integration of the pulse with SSI sequences (e.g., spoiled gradient-echo).
• Simulations, phantom experiments, and in vivo imaging (brain, cartilage, angiography) at 3T.

Main Results:

• The adapted RF spoiling is essential for achieving steady state in fat sat SSI sequences.
• The combined pulse robustly provides fat suppression and MT contrast, even with field inhomogeneity.
• Demonstrated efficacy in various in vivo imaging scenarios.

Conclusions:

• SSI sequences combined with the fat sat and MT contrast pulse and adapted RF spoiling offer robust fat suppression and MT contrast.
• This approach is effective even in the presence of magnetic field inhomogeneity.
• Enables improved image quality for diverse clinical applications.