The Canadian Dementia Imaging Protocol: Harmonizing National Cohorts

Background Harmonized protocols to collect imaging data must be devised, employed, and maintained in multicentric studies to reduce interscanner variability in subsequent analyses. Purpose To present a standardized protocol for multicentric research on dementia linked to neurodegeneration in aging, harmonized on all three major vendor platforms. The protocol includes a common procedure for qualification, quality control, and quality assurance and feasibility in large‐scale studies. Study Type Prospective. Subjects The study involved a geometric phantom, a single individual volunteer, and 143 cognitively healthy, mild cognitively impaired, and Alzheimer's disease participants in a large‐scale, multicentric study. Field Strength/Sequences MRI was perform with 3T scanners (GE, Philips, Siemens) and included 3D T1w, PD/T2w, T2*, T2w‐FLAIR, diffusion, and BOLD resting state acquisitions. Assessment Measures included signal‐ and contrast‐to‐noise ratios (SNR and CNR, respectively), total brain volumes, and total scan time. Statistical Tests SNR, CNR, and scan time were compared between scanner vendors using analysis of variance (ANOVA) and Tukey tests, while brain volumes were tested using linear mixed models. Results Geometric phantom T1w SNR was significantly (P