Knowledge Transfer between Datasets for Learning-based Tissue Microstructure Estimation

TL;DR

This paper proposes a method for transferring knowledge from high-quality to low-quality diffusion MRI datasets to enable tissue microstructure estimation without the need for training scans in the target dataset.

Contribution

The authors introduce a novel approach that interpolates high-quality source data to match target acquisition schemes, facilitating deep learning-based tissue microstructure estimation without target training data.

Findings

Effective transfer of microstructure estimation across datasets.

Improved estimation accuracy on low-quality dMRI scans.

Demonstrated benefits on brain dMRI data.

Abstract

Learning-based approaches, especially those based on deep networks, have enabled high-quality estimation of tissue microstructure from low-quality diffusion magnetic resonance imaging (dMRI) scans, which are acquired with a limited number of diffusion gradients and a relatively poor spatial resolution. These learning-based approaches to tissue microstructure estimation require acquisitions of training dMRI scans with high-quality diffusion signals, which are densely sampled in the q-space and have a high spatial resolution. However, the acquisition of training scans may not be available for all datasets. Therefore, we explore knowledge transfer between different dMRI datasets so that learning-based tissue microstructure estimation can be applied for datasets where training scans are not acquired. Specifically, for a target dataset of interest, where only low-quality diffusion signals are acquired without training scans, we exploit the information in a source dMRI dataset acquired with high-quality diffusion signals. We interpolate the diffusion signals in the source dataset in the q-space using a dictionary-based signal representation, so that the interpolated signals match the acquisition scheme of the target dataset. Then, the interpolated signals are used together with the high-quality tissue microstructure computed from the source dataset to train deep networks that perform tissue microstructure estimation for the target dataset. Experiments were performed on brain dMRI scans with low-quality diffusion signals, where the benefit of the proposed strategy is demonstrated.