MarkVCID cerebral small vessel consortium: II. Neuroimaging protocols.

Area of Science:

• Neuroimaging
• Biomarker Development
• Vascular Contributions to Cognitive Impairment and Dementia (VCID)

Background:

• Cerebral small vessel diseases (CSVD) are a primary cause of vascular contributions to cognitive impairment and dementia (VCID).
• Validated biomarkers are essential for effective multicenter studies to prevent and treat VCID.
• Existing neuroimaging biomarkers, particularly MRI, lack sufficient validation for repeatability and reproducibility across different settings.

Purpose of the Study:

• To describe and validate the neuroimaging protocols developed by the MarkVCID consortium for assessing CSVD.
• To establish harmonized multicenter study protocols for Magnetic Resonance Imaging (MRI) and Optical Coherence Tomography Angiography (OCTA).
• To ensure the instrumental validity (repeatability, reproducibility) of neuroimaging biomarkers for future multicenter trials.

Main Methods:

• Developed standardized MRI protocols including T1-weighted, T2-weighted FLAIR, DWI, T2*-weighted GRE, T2w, and BOLD-CVR sequences with harmonized parameters for 3 Tesla scanners.
• Established rigorous procedures for instrumental validation of MRI biomarkers, including inter-rater reliability, test-retest repeatability, and inter-scanner reproducibility.
• Developed OCTA protocols for visualizing retinal capillaries as a surrogate for cerebral microvasculature, including procedures for instrumental validation and data de-identification.

Main Results:

• The MarkVCID consortium successfully established harmonized MRI and OCTA protocols with defined parameters for multiple scanner models.
• Rigorous instrumental validation procedures were implemented to assess inter-rater reliability, test-retest repeatability, and inter-scanner reproducibility for both MRI and OCTA.
• The developed protocols are designed for translation to multicenter trials, providing a template for generating comparable neuroimaging data.

Conclusions:

• The MarkVCID neuroimaging protocols provide a validated framework for assessing CSVD biomarkers in multicenter settings.
• Standardized MRI and OCTA procedures enhance the reliability and comparability of data crucial for VCID research and therapeutic development.
• These protocols will facilitate future interventional trials by ensuring robust and reproducible neuroimaging biomarker measurements.