2D CAIPI accelerated 3D multi-slab diffusion weighted EPI combined with qModeL reconstruction for fast high...

Area of Science:

• Medical Imaging
• Diffusion Weighted Imaging

Background:

• 3D multi-slab diffusion weighted imaging (3D ms-DWI) provides high signal-to-noise ratio efficiency and isotropic spatial resolution.
• Achieving high angular resolution in 3D ms-DWI is limited by prolonged scan times.

Purpose of the Study:

• To develop 6D k-q space acceleration strategies for 3D ms-DWI.
• To enable applications requiring simultaneous high spatial (1 mm isotropic) and angular (>30 directions) resolutions by reducing scan time.

Main Methods:

• Implemented non-uniform 3D k_y-k_z under-sampling with shot-selective 2D CAIPI.
• Utilized 2D navigators for inter-shot phase-compensation and incorporated phase into a model-based 3D multi-shot reconstruction.
• Extended reconstruction to joint q-space reconstruction with spatial total variation and deep-learned q-space regularization.

Main Results:

• The proposed reconstruction achieved adequate phase-compensation in accelerated 2D CAIPI and k_y-k_z under-sampled cases.
• Retrospective experiments demonstrated k-q accelerations up to a factor of 12 with <3% reconstruction error.
• Achieved a 3-fold reduction in scan time for high spatial and angular resolution experiments.

Conclusions:

• The developed method enables 3D ms-DWI for high k-q resolution applications.
• Scan times are reduced by approximately 3 times, facilitating advanced neuroimaging.