Improved Assessment of Longitudinal Spinal Cord Atrophy in Multiple Sclerosis Using a Registration-Based Approach:...

Area of Science:

• Neuroimaging
• Medical Physics
• Neurology

Background:

• Cervical cord atrophy progression measurement is crucial for monitoring neurodegeneration in multiple sclerosis (MS).
• Existing methods for measuring cord atrophy may lack the necessary precision for clinical applications.

Purpose of the Study:

• To compare a novel registration-based (Reg) method against two established techniques (active surface [AS] and propagation segmentation [PropSeg]) for quantifying cervical cord atrophy changes over time in MS.
• To evaluate the accuracy and reliability of the Reg method in measuring MS-related neurodegeneration.

Main Methods:

• A retrospective study involving two cohorts of healthy controls (HC) and MS patients (totaling 91 HC and 191 MS patients) across different European sites.
• 3D T1-weighted gradient echo sequences were acquired at 1.5T and 3.0T. Percentage cord area changes (PCACs) were calculated using Reg, AS, and PropSeg methods over follow-up periods of approximately 1-2 years.
• Linear regression and mixed-effect models were employed to assess annualized PCACs, effect sizes, and reproducibility, with intra- and inter-observer agreement evaluated.

Main Results:

• The registration-based (Reg) method demonstrated lower annualized percentage cord area changes (PCACs) with smaller standard errors compared to AS and PropSeg methods in MS patients at both 1.5T and 3.0T.
• Effect sizes were larger, and required sample sizes for clinical trials were smaller when using the Reg method.
• The Reg method achieved superior reproducibility, with intra- and inter-observer agreement exceeding 0.96, compared to 0.72-0.91 for the AS method.

Conclusions:

• The registration-based method provides a more reliable and sensitive approach for measuring cervical cord atrophy progression in multiple sclerosis.
• This advanced imaging analysis technique holds significant promise for enhancing the monitoring of neurodegeneration and the assessment of treatment efficacy in future MS clinical studies.