Related Experiment Video
Updated: Jun 13, 2026
Dynamic Visual Tests to Identify and Quantify Visual Damage and Repair Following Demyelination in Optic Neuritis Patients
Published on: April 14, 2014
Neurite Orientation Dispersion and Density Imaging for Assessing Acute Inflammation and Lesion Evolution in MS
S Sacco1,2, E Caverzasi1, N Papinutto1
1From the Department of Neurology (S.S., E.C., N.P., C.C., A.B., T.G., S.C., C.A., G.K., J.M., W.A.S., R.M.B., J.M.G., D.S.G., A.J.G., E.W., M.R.W., S.S.Z, B.A.C., S.L.H., and R.G.H.), University of California, San Francisco Weill Institute for Neurosciences, University of California, San Francisco, California.
Background And Purpose:
MR imaging is essential for MS diagnosis and management, yet it has limitations in assessing axonal damage and remyelination. Gadolinium-based contrast agents add value by pinpointing acute inflammation and blood-brain barrier leakage, but with drawbacks in safety and cost. Neurite orientation dispersion and density imaging (NODDI) assesses microstructural features of neurites contributing to diffusion imaging signals. This approach may resolve the components of MS pathology, overcoming conventional MR imaging limitations.
Materials And Methods:
Twenty-one subjects with MS underwent serial enhanced MRIs (12.6 ± 9 months apart) including NODDI, whose key metrics are the neurite density and orientation dispersion index. Twenty-one age- and sex-matched healthy controls underwent unenhanced MR imaging with the same protocol. Fifty-eight gadolinium-enhancing and non-gadolinium-enhancing lesions were semiautomatically segmented at baseline and follow-up. Normal-appearing WM masks were generated by subtracting lesions and dirty-appearing WM from the whole WM.
Results:
The orientation dispersion index was higher in gadolinium-enhancing compared with non-gadolinium-enhancing lesions; logistic regression indicated discrimination, with an area under the curve of 0.73. At follow-up, in the 58 previously enhancing lesions, we identified 2 subgroups based on the neurite density index change across time: Type 1 lesions showed increased neurite density values, whereas type 2 lesions showed decreased values. Type 1 lesions showed greater reduction in size with time compared with type 2 lesions.
Conclusions:
NODDI is a promising tool with the potential to detect acute MS inflammation. The observed heterogeneity among lesions may correspond to gradients in severity and clinical recovery after the acute phase.
Insights
Neurite orientation dispersion and density imaging (NODDI) shows promise in detecting acute multiple sclerosis (MS) inflammation. This advanced MRI technique reveals lesion heterogeneity, potentially indicating varying severity and recovery.
Area of Science:
- Neuroimaging
- Radiology
- Neurology
Background:
- Conventional MRI has limitations in assessing axonal damage and remyelination in multiple sclerosis (MS).
- Gadolinium-based contrast agents highlight acute inflammation but pose safety and cost concerns.
- Neurite orientation dispersion and density imaging (NODDI) offers a novel approach to evaluate white matter microstructure.
Purpose of the Study:
- To investigate the utility of NODDI in characterizing MS lesions and detecting acute inflammation.
- To explore the potential of NODDI to overcome limitations of conventional MRI in MS assessment.
Main Methods:
- Serial enhanced MRIs, including NODDI, were performed on 21 MS patients over 12.6 months.
- NODDI metrics (neurite density index, orientation dispersion index) were analyzed in enhancing and non-enhancing lesions.
- Comparison with 21 healthy controls using similar MRI protocols.
Main Results:
- The orientation dispersion index was significantly higher in gadolinium-enhancing lesions compared to non-enhancing ones (AUC=0.73).
- Two lesion subgroups were identified based on neurite density index changes over time.
- Type 1 lesions (increased neurite density) showed a greater reduction in size compared to Type 2 lesions (decreased neurite density).
Conclusions:
- NODDI is a promising tool for detecting acute MS inflammation.
- Lesion heterogeneity observed with NODDI may reflect varying MS severity and clinical recovery potential.
