Feasibility of in vivo multi-parametric quantitative magnetic resonance imaging of the healthy sciatic nerve with a unified signal readout protocol

Magnetic resonance neurography (MRN) has been used successfully over the years to investigate the peripheral nervous system (PNS) because it allows early detection and precise localisation of neural tissue damage. However, studies demonstrating the feasibility of combining MRN with multi-parametric quantitative magnetic resonance imaging (qMRI) methods, which provide more specific information related to nerve tissue composition and microstructural organisation, can be invaluable. The translation of emerging qMRI methods previously validated in the central nervous system to the PNS offers real potential to characterise in patients in vivo the underlying pathophysiological mechanisms involved in a plethora of conditions of the PNS. The aim of this study was to assess the feasibility of combining MRN with qMRI to measure diffusion, magnetisation transfer and relaxation properties of the healthy sciatic nerve in vivo using a unified signal readout protocol. The reproducibility of the multi-parametric qMRI protocol as well as normative qMRI measures in the healthy sciatic nerve are reported. The findings presented herein pave the way to the practical implementation of joint MRN-qMRI in future studies of pathological conditions affecting the PNS.

Automated summary

Magnetic resonance neurography (MRN) has been successfully used to investigate the peripheral nervous system (PNS) by early detecting and accurately locating neural tissue damage. Combining MRN with multi-parametric quantitative magnetic resonance imaging (qMRI) methods, which provide specific information on nerve tissue composition and microstructural organization, is invaluable. This study aimed to assess the feasibility of combining MRN with qMRI to measure diffusion, magnetization transfer, and relaxation properties of the healthy sciatic nerve in vivo. The findings pave the way for the practical implementation of joint MRN-qMRI in future studies of PNS pathological conditions.