Slice accelerated diffusion-weighted imaging at ultra-high field strength.

Area of Science:

• Magnetic Resonance Imaging
• Neuroimaging
• Diffusion MRI

Background:

• 7T MRI enables very high isotropic resolution diffusion MRI (dMRI).
• Extensive brain coverage requires many slices, leading to long acquisition times.
• Simultaneous multi-slice (SMS) imaging is a promising technique to reduce scan time.

Purpose of the Study:

• To investigate the feasibility of SMS dMRI at 7T for high-resolution brain imaging.
• To reduce acquisition time (TA) while maintaining image quality and minimizing distortions.
• To address challenges of radiofrequency power deposition and SAR constraints at ultra-high fields.

Main Methods:

• Utilized a combination of zoomed and parallel imaging with blipped-CAIPI for SMS acquisition.
• Employed low SAR multislice Power Independent of Number of Slices (PINS) RF pulses to overcome SAR limitations at 7T.
• Acquired in vivo dMRI data at various isotropic spatial resolutions and high angular resolution.

Main Results:

• Demonstrated successful in vivo dMRI acquisition with SMS acceleration at 7T.
• Achieved high isotropic spatial resolution with minimal distortions.
• Presented data suitable for detecting complex fiber crossings.

Conclusions:

• SMS dMRI at 7T significantly reduces scan time compared to conventional methods.
• Image quality is preserved, demonstrating the effectiveness of the developed low SAR RF pulses.
• This technique facilitates efficient high-resolution neuroimaging at ultra-high field strengths.