Imaging Data
Standardized Centralized Alzheimer's & Related Dementias Neuroimaging (SCAN)
The SCAN Initiative: Standardized MRI and PET Data
The SCAN initiative is a collaboration between NACC, UC Berkeley, Mayo Clinic, University of Michigan, UC Davis, and the Laboratory of Neuro Imaging (LONI), funded by the National Institute on Aging. NACC provides the infrastructure for SCAN data integration, reporting, and sharing back to ADRCs and to the research community. The goal of SCAN is to enable harmonized PET and MRI image acquisition across the ADRC Program and develop the infrastructure for image curation and analysis. This initiative will allow standard image data to be combined across Centers and integrated with UDS and other data streams within the NACC repository, all of which can also be shared with researchers around the world to advance the field.
What Is SCAN Data?
ADRCs acquire and upload SCAN-compliant images to a portal hosted by LONI at the University of Southern California where they are de-identified and defaced by the Aging and Dementia Imaging Research (ADIR) laboratory at Mayo Clinic. The PET and MRI laboratories at the University of Michigan and the ADIR Laboratory then process the images for quality assurance and harmonization. Following this, the PET laboratory at UC Berkely and the MRI laboratories at Mayo Clinic and UC Davis analyze the images to produce analysis results such as brain volumes, cortical thickness, surface area, and Standardized Uptake Value Ratio (SUVR) data. summary, QC, analysis (volumes and SUVRs), and access to defaced SCAN images.
What SCAN Data Is Available at NACC?
Submit a data request to receive the SCAN Quick-Access files including:
- MRI and PET analysis results such as brain volumes, cortical thickness, surface area, and SUVRs.
- MRI and PET numerical data such as summary and quality control (QC) information.
- Defaced MR and PET images.
Mixed Protocol (Non-Standard) MRI and PET Data
What Is Mixed Protocol MRI and PET Data?
NACC collects and shares MRI and/or PET data that does not adhere to the SCAN/CLARiTI protocols or was collected prior to January 2021. We have partnered with imaging experts such as Dr. Charles DeCarli at the University of California at Davis, Dr. Beth Mormino at Stanford, and Dr. Tim Hohman at Vanderbilt University to clean, label, and produce harmonized analysis results for mixed protocol MRI and PET data that has been submitted to NACC.
Imaging data collection and acquisition protocols vary by ADRC; thus, packages of mixed protocol files at NACC may include:
- For MRI: T1-weighted, FLAIR, DTI, T2, or other MR series (and any combination thereof).
- For PET: Tau and amyloid scans (or a combination).
- For both MRI and PET: Participants may or may not have multiple scan sessions in the NACC database.
What Data Is Available at NACC?
Images, along with volumetric summary measures, are available for a subset of participants in the Uniform Data Set. Both DICOM and NIFTI formats are available.
Amyloid Positron emission tomography (PET) scans and (coming soon!) tau PET scan and Standard Uptake Value Ratios (SUVRs), are available for a subset of participants in the Uniform Data Set.
Images are archived by NACCID and study or scan date (.zip), delivered via a cloud-based distribution system, and linked to any requested UDS, FTLD, or NP data.
Additional Imaging Resources
Use the NACC MRI Preview System for an estimate of the number of available mixed protocol scans that meet your image-type and participant criteria.
Real-time SCAN Public Dashboard: See how much SCAN-compliant PET and MRI data from across the ADRC Program has passed QC and is available for analysis.
Mixed Protocol amyloid PET scans are also available via data request for a small number of participants.
Consortium for Clarity in ADRD Research Through Imaging (CLARiTI) Data
The Consortium for Clarity in ADRD Research Through Imaging (CLARiTI) is a multi-site imaging observational study involving all 36 ADRC sites with a special focus on multi-etiology dementia. CLARiTI collects standard MR and PET images, blood biomarkers, and advanced MRI data. All images, data, and biospecimen collected on ADRC participants through CLARiTI will be integrated with the NACC Data Platform and will be available to researchers.
NACC is partnering closely with the CLARiTI initiative to advance AD/ADRD discovery and translation. NACC is actively expanding its core infrastructure to provide comprehensive and streamlined operational and informatics support for CLARiTI. Additionally, NACC facilitated ADRC engagement with the CLARiTI project and amplified CLARiTI communications for the ADRC Program using NACC’s extensive network and communications infrastructure. CLARiTI is leveraging NACC infrastructure to accelerate and track MRI and PET image submissions from the ADRCs and to make additional image analysis and summary results available to AD/ADRD researchers through the NACC DFD.
The Alzheimer's Disease Sequencing Project Phenotype Harmonization Consortium (ADSP-PHC)
The Alzheimer's Disease Sequencing Project Phenotype Harmonization Consortium (ADSP-PHC, U24-AG074855) was established to harmonize the rich endophenotypic data across cohort studies to enable modern genomic analyses of AD/ADRD. Drs. Timothy Hohman, Mike Cuccaro, and Arthur Toga lead this consortium. Only a subset of NACC participants have harmonized cognitive, fluid biomarker, neuropathology, cardiovascular risk factor, and neuroimaging scores available in this dataset. Please note that NACC was not involved in this harmonization project.