Integrated and efficient diffusion-relaxometry using ZEBRA

TL;DR

ZEBRA is an integrated MRI sequence that combines diffusion and relaxometry measurements, significantly accelerating data acquisition and enabling detailed tissue microstructure analysis for research and clinical use.

Contribution

The paper introduces ZEBRA, a fully integrated MRI sequence that efficiently combines diffusion and relaxometry sampling, improving speed and flexibility over existing methods.

Findings

Achieved a 20-fold acceleration in data acquisition.

Successfully acquired in-vivo brain data demonstrating the method's effectiveness.

Produced detailed parametric maps and clustering results.

Abstract

The emergence of multiparametric diffusion models combining diffusion and relaxometry measurements provide powerful new ways to explore tissue microstructure with the potential to provide new insights into tissue structure and function. However, their ability to provide rich analyses and the potential for clinical translation critically depends on the availability of efficient, integrated, multi-dimensional acquisitions. We propose a fully integrated sequence simultaneously sampling the acquisition parameter spaces required for T1 and T2* relaxometry and diffusion MRI. Slice-level interleaved diffusion encoding, multiple spin/gradient echoes and slice-shuffling are combined for higher efficiency, sampling flexibility and enhanced internal consistency. In-vivo data was successfully acquired on healthy adult brains. Obtained parametric maps as well as clustering results demonstrate the potential of the technique regarding its ability to provide eloquent data with an acceleration of roughly 20 compared to conventionally used approaches. The proposed integrated acquisition, called ZEBRA, offers significant acceleration and flexibility compared to existing diffusion-relaxometry studies and thus facilitates wider use of these techniques both for research-driven and clinical applications.