The Canadian Dementia Imaging Protocol: Harmonizing National Cohorts

Area of Science:

• Neuroimaging
• Medical Imaging
• Radiology

Background:

• Multicentric studies require harmonized imaging protocols to minimize interscanner variability.
• Standardization is crucial for reliable analysis of neurodegenerative disease progression.

Purpose of the Study:

• To present a standardized, harmonized MRI protocol for multicentric dementia research across major vendor platforms (GE, Philips, Siemens).
• To establish a common procedure for scanner qualification, quality control, quality assurance, and assess feasibility in large-scale studies.

Main Methods:

• Prospective study involving a geometric phantom, one volunteer, and 143 participants (healthy, MCI, AD).
• Utilized 3T scanners (GE, Philips, Siemens) with various MRI sequences (3D T1w, PD/T2w, T2w-FLAIR, diffusion, BOLD).
• Assessed signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), brain volumes, and scan time.

Main Results:

• Significant differences in phantom T1w SNR between Philips and Siemens scanners were observed.
• Volunteer T1w CNR varied by region and vendor, with Siemens higher in subcortical and Philips in cortical regions.
• No significant differences in total brain volumes or average scan time were found between vendors or cognitive groups.

Conclusions:

• The harmonized Canadian Dementia Imaging Protocol (CDIP) provides quality MRI data for studies on aging, neurodegeneration, and other brain changes.
• The protocol, including manuals and exam cards, is freely available to facilitate multicentric research.