Multiple B-Value Model-Based Residual Network (MORN) for Accelerated High-Resolution Diffusion-Weighted Imaging

Insights

A novel deep learning model, the Multiple b-value mOdel-based Residual Network (MORN), reconstructs high-resolution Diffusion Weighted Imaging (DWI) from undersampled data. This method improves image quality and shows promise for clinical applications in neuroimaging.

Area of Science:

  • Magnetic Resonance Imaging (MRI)
  • Medical Image Reconstruction
  • Artificial Intelligence in Radiology

Background:

  • Single-Shot Echo Planar Imaging (SSEPI) for Diffusion Weighted Imaging (DWI) suffers from low resolution and distortions.
  • Multi-Shot EPI (MSEPI) offers better resolution but requires longer scan times.
  • Efficient reconstruction of high-quality DWI is crucial for clinical diagnosis.

Purpose of the Study:

  • To develop a deep learning model for simultaneous reconstruction of multiple b-value, high-resolution DWI from undersampled k-space data.
  • To integrate Parallel Imaging (PI) with a residual U-net architecture for multi-coil data reconstruction.
  • To validate the model's performance against existing reconstruction methods and in clinical cases.

Main Methods:

  • Proposed a Multiple b-value mOdel-based Residual Network (MORN) incorporating PI and a residual U-net.
  • Utilized MUltiplexed Sensitivity-Encoding (MUSE) reconstructed Multi-Shot DWI (MSDWI) for supervision.
  • Employed asymmetric concatenations across b-values and a combined loss function for feature transfer.
  • Trained and validated the MORN on 32 healthy cases and tested on 6 tumor patients.

Main Results:

  • MORN significantly outperformed SENSE, SENSE-GAN, and VSNet in Peak Signal-to-Noise Ratio (PSNR) and Structural SIMilarity (SSIM).
  • Reconstructed apparent diffusion coefficient (ADC) maps showed superior quality.
  • Consistent fractional anisotropy (FA) and mean diffusivity (MD) were achieved using the pre-trained model for multiple diffusion directions.

Conclusions:

  • The MORN model enables high-resolution, multiple b-value DWI reconstruction from undersampled data.
  • The method demonstrates superior performance compared to conventional and deep learning-based techniques.
  • MORN shows significant potential for clinical application in neuroimaging, particularly for tumor assessment.