Neurite Orientation Dispersion and Density Imaging in Multiple Sclerosis: A Systematic Review

Diffusion-weighted imaging has been applied to investigate alterations in multiple sclerosis (MS). In the last years, advanced diffusion models were used to identify subtle changes and early lesions in MS. Among these models, neurite orientation dispersion and density imaging (NODDI) is an emerging approach, quantifying specific neurite morphology in both grey (GM) and white matter (WM) tissue and increasing the specificity of diffusion imaging. In this systematic review, we summarized the NODDI findings in MS. A search was conducted on PubMed, Scopus, and Embase, which yielded a total number of 24 eligible studies. Compared to healthy tissue, these studies identified consistent alterations in NODDI metrics involving WM (neurite density index), and GM lesions (neurite density index), or normal-appearing WM tissue (isotropic volume fraction and neurite density index). Despite some limitations, we pointed out the potential of NODDI in MS to unravel microstructural alterations. These results might pave the way to a deeper understanding of the pathophysiological mechanism of MS.

Automated summary

Diffusion-weighted imaging has been used to study alterations in multiple sclerosis (MS), and neurite orientation dispersion and density imaging (NODDI) is an emerging approach that quantifies specific neurite morphology. This systematic review summarized the NODDI findings in MS, identifying consistent alterations in NODDI metrics in white matter and grey matter lesions. Despite limitations, NODDI has the potential to reveal microstructural alterations in MS and improve our understanding of its pathophysiological mechanism.