Diffusion Basis Restricted Fraction as a Putative Magnetic Resonance Imaging Marker of Neuroinflammation:...

Area of Science:

• Neuroimaging
• Biomedical Engineering
• Radiology

Background:

• Diffusion basis spectrum imaging-derived restricted fraction (DBSI-RF) isolates water signals from cellular crowding, suggesting its potential as a magnetic resonance imaging (MRI) marker for neuroinflammation.
• Neuroinflammation is implicated in various neurological disorders, necessitating reliable imaging biomarkers for diagnosis and monitoring.

Purpose of the Study:

• To conduct a narrative review evaluating animal and human studies that compare DBSI-RF with histopathological benchmarks and clinical parameters.
• To assess the diagnostic and prognostic accuracy of DBSI-RF in conditions characterized by neuroinflammation.

Main Methods:

• Systematic review of studies comparing DBSI-RF with histopathology and clinical data in animal models and human subjects.
• Analysis of DBSI-RF performance across diverse neurological conditions including inflammatory demyelination, viral encephalitis, traumatic brain injury, and neurodegenerative disorders.

Main Results:

• DBSI-RF demonstrated moderate to strong correlations with immune cell density across various inflammatory conditions.
• The technique effectively distinguished between inflammation and other pathologies like demyelination or axonal damage.
• In acute multiple sclerosis, DBSI-RF aided in predicting lesion evolution and classifying subtypes with high accuracy, even in deep-learning models.

Conclusions:

• DBSI-RF shows potential as a sensitive MRI biomarker for detecting neuroinflammation, including subclinical changes.
• Its ability to map coexisting pathologies like edema, demyelination, and axon loss is a significant strength.
• Further standardized, multicenter, prospective trials and external validation are warranted to confirm its diagnostic and prognostic utility.