Forms and documentation
Imaging and biomarker data are available on a subset of UDS participants. These data are most appropriately described as a convenience sample, voluntarily submitted by several Alzheimer’s Disease Research Centers (ADRCs). MRI, amyloid PET, and tau PET scans and data are available on a subset of UDS participants. Biomarker data is in the form of CSF values for Abeta, P-tau, and T-tau. Limited genetic data is available at NACC (i.e., APOE genotype, recorded for more than 75% of participants); more genetic data are available from our partners.
Researcher’s Data Dictionary — SCAN MRI
The Researcher’s Data Dictionary — SCAN MRI includes MRI quality control variables associated with images stored at LONI, as well as variables for volume, cortical thickness, and surface area measurements. Imaging data collection and acquisition were done using standardized SCAN protocols. Participants may have MRI scans from multiple dates.
The SCAN MR analysis team performs standard processing of all MR images that have passed QC using FreeSurfer to provide standard readouts. These include the parcellations of regional brain volumes, cortical thickness and surface area for 31 bilateral gray matter regions from the Desikan-Killiany atlas.
NOTE: Due to the processing time needed to perform defacing, QC, and analysis on submitted data, not all data that has been submitted and/or passed through QC has analysis data associated with it.
Please refer to the following resources for more details:
Researcher’s Data Dictionary — SCAN PET
The Researcher’s Data Dictionary — SCAN PET includes PET quality control variables associated with images stored at LONI, as well as SUVR variables. Imaging data collection and acquisition were done using standardized SCAN protocols. Participants may have PET scans from multiple dates.
NOTE: Due to the processing time needed to perform defacing, QC, and analysis on submitted data, not all data that has been submitted and/or passed through QC has analysis data associated with it.
Please refer to the following resources for more details:
Researcher’s Data Dictionary — Imaging Data (RDD-ID)
The Researcher’s Data Dictionary — Imaging Data (RDD-ID) includes MRI and PET variables (e.g., year of MRI scan, year of amyloid PET scan) associated with DICOM files stored at NACC. Also included are MRI variables that provide volume values (e.g., hippocampal volume) for the subset of DICOM files stored at NACC for which volumetric analysis has been completed. Imaging data collection and acquisition protocols vary by ADRC, Packages of MRI files at NACC may include T1-weighted, FLAIR, DTI, T2, or other MR series (and any combination thereof). Participants may also have MRI or PET scans from multiple dates.
For a subset of the MRIs, calculated summary data are also available. The calculations were performed by then IDeA Lab (Director: Charles DeCarli, MD; University of California, Davis), following ADNI protocols. For specific methods used to perform these calculations, please see this document provided by the IDeA Lab.
An older version of the RDD-ID is also available for researchers using data sets that include variables that were available from 2015 to May 2019.
Data Element Dictionary — CSF (DED-CSF)
The Data Element Dictionary — CSF (DED-CSF) includes data on UDS participants who have CSF values for Abeta, P-tau, and T-tau. Please note that CSF assay methods are not standardized across the ADRCs, and that some participants may have CSF values from multiple dates.
Researcher’s Data Dictionary — Genetic Data (RDD-Gen)
The Researcher’s Data Dictionary — Genetic Data (RDD-Gen) describes variables that contain either genetic data (APOE genotype) or information about the availability of genetic data that can be obtained, by request, from the Alzheimer’s Disease Genetics Consortium (ADGC), or the National Institute of Aging Genetics of Alzheimer’s Disease Data Storage Site (NIAGADS).