High spatial resolution diffusion weighted imaging on clinical 3 T MRI scanners using multislab spiral acquisitions

Area of Science:

• Magnetic Resonance Imaging
• Neuroimaging
• Medical Physics

Background:

• Diffusion weighted imaging (DWI) is crucial for neuroimaging.
• Achieving high spatial resolution (sub-mm) with adequate signal-to-noise ratio (SNR) on clinical 3T MRI systems remains challenging.
• Existing 2D acquisition methods often compromise SNR efficiency or resolution.

Purpose of the Study:

• To develop a novel DWI sequence for SNR-efficient sub-millimeter resolution imaging on clinical 3T MRI scanners.
• To compare the proposed technique's SNR efficiency against conventional 2D DWI methods.
• To demonstrate the technique's capability in acquiring high-resolution diffusion tensor imaging (DTI) datasets.

Main Methods:

• A multislab, multishot pulsed gradient spin echo DWI sequence with spiral readouts was implemented.
• Long data readouts and field-inhomogeneity-corrected reconstruction were used to maintain image quality and reduce acquisition time.
• Integrated navigator data enabled motion-induced phase correction for high-resolution acquisitions.

Main Results:

• The proposed DWI technique demonstrated 71% higher SNR efficiency compared to standard 2D echo-planar imaging (EPI).
• High-resolution DTI datasets were successfully acquired with isotropic resolutions of 1.25 mm and 0.8 mm.
• The method effectively addressed distortions and motion artifacts inherent in high-resolution, long-readout acquisitions.

Conclusions:

• The developed DWI approach enables SNR-efficient sub-millimeter resolution imaging on clinical 3T systems.
• This technique offers improved image quality and robustness for advanced neuroimaging applications requiring high spatial detail.
• The method represents a significant advancement for in vivo DWI and DTI at ultra-high resolutions.