Postmortem verification of MS cortical lesion detection with 3D DIR

Area of Science:

• Neurology
• Radiology
• Pathology

Background:

• Multiple sclerosis (MS) is a chronic inflammatory disease affecting the central nervous system.
• Cortical lesions (CLs) are a significant hallmark of MS pathology.
• Accurate detection of CLs is crucial for understanding MS progression and for developing effective treatments.

Purpose of the Study:

• To evaluate the sensitivity and specificity of 3D double inversion recovery (DIR) MRI.
• To compare 3D DIR with 3D fluid-attenuated inversion recovery (FLAIR) MRI for detecting MS cortical lesions.
• To validate MRI findings against histopathology using postmortem brain samples.

Main Methods:

• Acquisition of 3D DIR and 3D FLAIR MRI sequences on fresh brain samples from 14 MS patients.
• Prospective and retrospective scoring of CLs by experienced raters blinded to histopathology.
• Classification of lesions as intracortical or mixed gray matter (GM)-white matter, and scoring of deep GM lesions.
• Direct comparison of MRI findings with detailed histopathological analysis.

Main Results:

• 3D DIR demonstrated a 1.6-fold higher sensitivity for MS CLs than 3D FLAIR (18% vs. 11.5%), improving to 37% with retrospective scoring (2.0-fold higher).
• Sensitivity for mixed GM-white matter lesions was 83% for 3D DIR versus 65% for 3D FLAIR, improving to 96% and 91% respectively with retrospective scoring.
• 3D DIR detected over twice as many purely intracortical lesions as 3D FLAIR, with this ratio increasing to over threefold upon retrospective scoring.
• The specificity of 3D DIR for MS CLs was determined to be 90%.

Conclusions:

• 3D DIR MRI is a highly pathologically specific imaging technique for MS.
• 3D DIR exhibits superior sensitivity in detecting MS cortical lesions compared to 3D FLAIR.
• This postmortem study validates 3D DIR as a valuable tool for MS research and potentially clinical diagnosis.