The participants in the BioFINDER cohorts undergo MR imaging (MRI) on the same 3T MR scanner to avoid inter-scanner variabilities in the results that are known from other large cohort studies. Cognitively healthy participants, as well as those with mild cognitive impairment and dementia are imaged at a 3T Siemens Trio scanner and all participants in the Parkinson cohort, including controls, are imaged at a 3T Siemens Skyra scanner.
The protocol at the Siemens Trio includes the following sequences: sagittal T1-weighted spin echo; axial T2-weighted FLAIR for assessment of focal pathology; coronal T2-weighted GRE for assessment of siderosis and microbleeds; T1-weighted 3D MP-RAGE for volumetric measurements; diffusion tensor imaging (DTI, 64 directions) and diffusion kurtosis imaging (DKI, 64 directions) for white matter alterations and structural connectivity; resting state functional MRI (rsfMRI) for estimation of functional connectivity; arterial spin labelling (ASL) to evaluate cerebral blood flow; single voxel 1H MR spectroscopy for assessment of metabolite concentrations in the precuneus.
The protocol at the Siemens Skyra includes the following sequences: sagittal T2-weighted spin echo; axial T2-weighted FLAIR for assessment of focal pathology; axial SWI for assessment of susceptibility changes; T1-weighted 3D MP-RAGE for volumetric measurements; diffusion tensor imaging (DTI, 32 directions) and diffusion kurtosis imaging with 3-shell HARDI data acquisition (DKI, 64 directions, 2500) for white matter alterations and structural connectivity; resting state functional MRI (rs-fMRI) for estimation of functional connectivity; arterial spin labelling (ASL) to evaluate cerebral blood flow.
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Resting-state functional MRI analysis showing reduced connectivity between the default mode network and hippocampus in amyloid-positive patients with mild cognitive impairment compared with amyloid-negative healthy elderly.