Data Sharing

The NACC Data Platform makes harmonized images and numerical summaries (e.g., Standardized Uptake Value Ratio ‘SUVRs’ and volumes) available to ADRCs and approved researchers around the world through the following mechanisms:

ADRC Portals: ADRCs can access and download SCAN data for their participants

• SCAN QC Dashboards: ADRCs can track and audit their image submission’s quality control (QC) status and other summary information in real-time.

• All SCAN Variables: Numerical values (SUVRs and volumes) will be accessible to ADRCs via the ADRC Portals for all their participants.

NACC Data Front Door: Researchers anywhere can access SCAN data for free

• SCAN Public Dashboard: The SCAN Public Dashboard provides researchers with up-to-date information on the number of participants with SCAN-compliant PET and MR images and the total number of images submitted by each ADRC to SCAN.

• Quick Access File Data Request System: Researchers can request SCAN data collected from all participating ADRCs, including summary, QC, and analysis (volumes and SUVRs) data. Starting in Fall 2024, researchers will also be able to access defaced SCAN images via this data request system.

• Cohort Selection Tool: Coming in 2025! A new self-service tool coming to NACC allowing researchers to perform cohort selection, data visualization, and provide access to raw data at NACC directly.

Raw images are stored at the Laboratory of Neuro Imaging (LONI). ADRCs and researchers interested in accessing the raw images will be able request them via LONI in the near future. NACC will provide updates on the availability of raw images as progress is made by SCAN, LONI, and NACC to ensure raw image data is de-identified before it is made available to the public.

SCAN Protocols

Prospective image files that meet SCAN acquisition protocols, regardless of the funding source, are submitted to LONI as part of this project. Existing images, and prospective images that don’t meet SCAN protocol, are instead submitted directly to NACC.
SCAN has a set of required acquisition schemes for PET and MR data. This includes required PET protocols for acquiring amyloid, tau, and fludeoxyglucose-18 (FDG) PET scans, and required MRI sequences for structural T1 and Fluid Attenuated Inversion Recovery (FLAIR) scans. Additional MRI sequences are optional. Analyzed data available to investigators will include:

• Regional measures of amyloid, tau, and FDG tracer uptake

• Brain volumes

• White matter hyperintensities

• Cerebral infarction

• Fractional anisotropy, cerebral blood flow, and functional connectivity (depending on the availability of advanced MRI sequences)

Current SCAN protocols are focused on widely accepted and applied biomarkers generally, but not exclusively, related to characterizing research participants in the A/T/N framework. To continue to support collaborative research, SCAN will base future directions on the needs and goals of the ADRC program. These may include other MRI techniques or PET tracers as best practices for their acquisition and analysis become available.

How to Participate

• Acquire Images

  Alzheimer’s Disease Research Centers participating in SCAN should refer to the MRI and PET checklist and manuals linked below for detailed SCAN image acquisition protocols.

  SCAN will troubleshoot prospectively with ADRCs to advise on making data SCAN compliant. Contact SCAN.

  Current SCAN Protocols

  MRI

  MRI Checklist and Manual

  All longitudinal scans must be performed on the same MRI scanner.

  Each MRI scanner must be certified and approved by SCAN. MR scanners that are now certified for ADNI 3 can be certified for SCAN using a phantom scan. MR scanners that have not been certified for ADNI 3 (or SCAN) must be certified using a human volunteer scan. This must be permissible using a local IRB – i.e. SCAN does not plan to create a central IRB nor will SCAN manage local IRB administrative proceedures.

  The Standard MRI protocol (using SCAN-specific parameters) is required. Your remaining scan time can be used for your site specific sequences.

  There are 2 options for SCAN MR – each site can choose which they prefer.

  Option 1: Site only required to do 2 primary SCAN sequences: T1 & FLAIR

  • The first 10 minutes of exam belongs to NIA/SCAN — this is when the SCAN T1 & FLAIR would be done

  • Remainder of exam is unique to site

  • SCAN would only collect and analyze T1 and FLAIR

  Option 2: Site may do full SCAN protocol (which mirrors ADNI)

  PET

  PET Checklist and Manual

  All longitudinal scans must be performed on the same PET scanner.

  Each PET scanner must be certified and approved by SCAN. ADNI approved PET scanners will not need to be re-certified.

  The following tracers and imaging protocols are all compatible with SCAN:

  	Suggested Target Dose ± 10%		Minimum injectable dose		Acquisition start-stop time post-injection (min)
  Tracer	mCi	MBq	mCi	MBq
  Amyloid Tracers
  PIB	15	555	8	300	40–60 or 50–70, 40–70
  Florbetapir	10	370	6	225	50–70
  Florbetaben	8	295	5	185	90–110
  NAV4694	8.1	300	6.5	240	40–70, 50–70
  Flutemetamol	5	185	4	150	90–110
  TAU Tracers
  Flortaucipir	10	370	6	225	80–100
  MK6240	5	185	4	150	70–90 or 90–110, 70–110
  PI2620	5	185	4	150	30–60, 45–75, 60–90, 45–90
  GTP1	7	260	5	185	60–90
  Glucose metabolism tracer
  FDG	5	185	4	150	30–45, 30–60

  NOTE: The SCAN MR protocol is the same as the Alzheimer’s Disease Neuroimaging Initiative (ADNI) protocol. The current protocol is ADNI 4. See this set of ADNI MR protocols created for various vendor/model/operating system options.

• Upload Images

  Submit SCAN-Compliant data to LONI

  Please carefully review the SCAN PET manual and the SCAN MRI manual to ensure that your data is compliant with the SCAN protocol and for uploading instructions.

  Only SCAN-compliant data should be submitted to the Laboratory of Neuro Imaging (LONI). Non-approved data (with or without approved data) will be quarantined. Images collected before 2021 do not meet SCAN-compliance criteria.

  Submit SCAN-compliant MRI/PET data

  Submit non–SCAN-compliant data directly to NACC

  SCAN does not accept data that is not prospectively collected and SCAN-compliant.

  Any data that that is 'heterogenous' or non-SCAN-compliant should be submitted to NACC.

  Submit Heterogenous MRI/PET data
• Track and audit image submissions

  Sites are responsible for auditing their submissions and making sure that the information is correct using the SCAN QC Dashboards.

  View the SCAN Dashboards

  Each ADRC can access their ADRC-specific SCAN QC Dashboards via the SCAN Public Dashboard.

  • These enable sites to track the QC status of their MRI and PET submissions, allowing them to rapidly address errors. They also serve as an auditable record of all SCAN MRI data submitted to SCAN by a given ADRC and are downloadable as a csv file.

  • NOTE: The ADRC-specific SCAN QC Dashboards are only available to ADRC staff with data access privileges. Please refer to the SCAN Dashboard Quick Access Guide for details.

• Access your SCAN data and analysis results

  All SCAN variables will soon be available via ADRC Portals. We anticipate this data being available by June 2024.

  In the meantime, ADRCs may access analysis results by submitting a data request via NACC’s Quick Access File Data Request System.

  Request SCAN data at NACC

  NOTE: Analysis results are calculated after defacing and QC has been performed on MR and PET images. Sites should expect a delay from when images are submitted to when analysis results are available.

Data Resources