White matter tract-specific quantitative analysis in multiple sclerosis: Comparison of optic radiation reconstruction...

Area of Science:

• Neuroimaging
• Neuroscience
• Medical Imaging

Background:

• Multiple sclerosis (MS) frequently impacts the posterior visual pathway, causing clinical and electrophysiological deficits.
• The visual pathway's structured retinotopic mapping makes it suitable for studying MS patho-mechanisms.
• Accurate in-vivo segmentation of optic radiations (OR) is crucial for MS research but challenged by white matter lesions.

Purpose of the Study:

• To optimize and compare two methods for optic radiation (OR) reconstruction: individual probabilistic tractography and template-based approaches.
• To assess the reliability of these methods for measuring volumetric and diffusivity parameters in MS patients.
• To determine the suitability of each method for clinical trials and practice.

Main Methods:

• Optimized and compared individual probabilistic tractography-based and template-based methods for OR reconstruction using clinical 3T scanner data.
• Applied OR segmentation to subjects with MS.
• Compared volumetric and diffusivity parameters between the two segmentation techniques.

Main Results:

• Both optimized probabilistic tractography and template-based methods provided highly comparable OR lesion volume and diffusivity measurements in MS subjects.
• Differences in reconstructed OR volumes were observed between the methods.
• The choice of method depends on the research question and dataset.

Conclusions:

• Optimized probabilistic tractography and template-based methods offer reliable and comparable in-vivo delineation of optic radiations in MS.
• Template-based methods are suitable for large datasets and can be used without diffusion MRI.
• Individual tractography allows for detailed analysis of diffusivity changes along specific fiber bundles.