SCAN Initiative Updates

The SCAN initiative is a collaboration between NACC, UC Berkeley, Mayo Clinic, University of Michigan, UC Davis, and LONI, and is funded by the National Institute on Aging. The goal of SCAN will be to promote standardization of PET and MR image acquisition so that images can be combined across multiple centers.

For more information about the SCAN initiative, please visit

Pipeline for standardized MRI/PET data collection, harmonization, analysis, and sharing.

When and how will SCAN summary data be returned to the ADRCs?

All ADRCs that have contributed data to SCAN were asked to perform a data audit for their SCAN submissions in March of 2023.
Once the SCAN data audit is complete, the SCAN team will integrate the audited data. After this step is completed, NACC will share your SCAN summary data back to your ADRC via REDCap.We anticipate that SCAN data will be returned to sites in Spring of 2023 and will keep ADRCs updated on the timeline.
In the future, SCAN summary data will be available to ADRCs in real-time in addition to your UDS data via the ADRC site-specific portals hosted in NACC's new data repository. Anticipated availability is summer of 2023.
If you have questions about the SCAN data audit, please contact
Data Front Door overview
New NACC Data Platform

What is the current process for submitting MRI/PET images?

As of March 17, 2023, sites will only be able to submit SCAN MRI/PET images to LONI for participants that already have a NACCID. This change will prevent errors (i.e., duplicate NACC IDs for participants, etc.) from being introduced into the database and the need for future SCAN data audits.
Please note that this is a temporary change. Sites are encouraged to continue collecting SCAN data on all of their participants but will not be able to submit data for participants without existing NACC IDs until LONI’s upload system is updated. The new LONI upload interface will minimize errors by requiring ADRCs to provide two identifying variables when submitting SCAN data.
As part of the communication that was sent out in March of 2023, NACC is gathering input from sites (via the survey linked in the email) that will be used to define requirements for this new LONI upload system.

What about non-SCAN compliant MRI/PET images that are submitted to NACC?

As of March 17, 2023, sites will only be able to submit non-SCAN compliant images to NACC for participants that already have existing NACC IDs.

How are identifiers used for the SCAN data?

When submitting MRI/PET images to SCAN via the LONI uploader, you are currently asked to enter the Subject ID or PTID. This number is different from the NACCID as described below:
  • Subject ID or PTID: this is the ADRC-managed participant ID, or "local ID". Formats vary by ADRC.
  • NACCID: this is the NACC-managed participant ID. It is a string with the prefix 'NACC' followed by 6 digits.
  • ADCID: this is the NACC-managed center ID. This is a two-digit number.
Each PTID and ADCID pair maps to a unique NACCID.

How are MRI and PET imaging submissions from ADRCs currently being tracked?

SCAN-compliant MRI/PET images submitted to LONI as part of the SCAN initiative:
  • The NACC monthly reports for each ADRC do not include the MRI/PET images submitted to LONI for the SCAN project in the image counts.
  • We will not be adding SCAN images to these static monthly reports because we are in the process of modernizing the NACC Data Platform and complete SCAN-compliant image counts will soon be available through the SCAN dashboards.
Non-SCAN compliant MRI/PET images submitted to NACC:
  • Your monthly report should currently reflect the correct number of legacy MRI and PET images that have been submitted to by your site to NACC.
  • There were previously some errors in these counts due to a bug. However, we believe all errors with counts of images at NACC have now been corrected.

How will MRI and PET imaging submissions be tracked in the future?

Coming soon as part of NACC's modernization. As NACC completes its transition onto our new modern data platform, we will launch the following resources:
  • Public SCAN Dashboard

    The Public SCAN Dashboard will track the number of SCAN-compliant MRI/PET images and the number of participants that images have been submitted for by each ADRC to LONI/NACC. The prototype for this dashboard was demonstrated at the 2022 Fall ADRC meeting. Anticipated availability is May 2023.

  • Private ADRC-Specific SCAN Dashboards:

    Each ADRC will also have access to private SCAN MRI and PET dashboards for their individual ADRC that will:

    • a) enable them to track the QC status of their MRI and PET submissions, allowing them to rapidly address errors, and
    • b) serve as an auditable record of all SCAN MRI data submitted to LONI/NACC by a given ADRC, downloadable as a csv file.

NACC is currently in discussion with NIA and the Imaging Steering Committee to determine how legacy MRI and PET images will be tracked and reported at NACC as we transition to our modern Data Platform. We will keep you updated!

How will ADRCs who contribute data to SCAN be acknowledged?

NACC will build off the current NACC Data Use Agreement (DUA) policy to provide researchers with a comprehensive list of ADRCs and other related grants who have contributed their data to SCAN. All researchers and person(s) requesting data from NACC (including SCAN data in the future) must accept the NACC DUA policy.
The current NACC DUA policy requires authors to include the following statement acknowledging the NACC grant and Center support in presentations and the acknowledgments section of manuscripts:

“The NACC database is funded by NIA/NIH Grant U24 AG072122. NACC data are contributed by the NIA-funded ADRCs: P30 AG...., etc.”

As part of the data audit communication that was sent out in March of 2023, NACC is gathering input from sites (via the survey linked in the email) that will be used to evaluate whether this proposed acknowledgement plan is acceptable to sites, prior to data being shared with researchers around the world.
If your site is involved in the SCAN initiative and you have additional grants or updates to include in the acknowledgements, please reach out to

How and when can researchers access SCAN data?

SCAN Summary Data (Volumes and SUVRs):

Phase 1: Researchers will be able to access SCAN summary data through the NACC Quick Access File data request system. We anticipate that this will be available by summer 2023.
NACC's Data Request System - learn more here
  • NACC currently provides UDS, neuropathology, and non-SCAN compliant MRI/PET data to researchers anywhere through our Quick Access File
  • It takes ~15 minutes for researcher to submit a data request
  • Researcher must sign a Data Use Agreement to access this data (NACC's current Data Use Agreement)
  • NACC has distributed more than 220 Quick Access Files since May 2022
Phase 2: NACC’s Data Front Door – Cohort selection, data visualization, and access
  • Allows self-service cohort selection
  • Provide the ability to download raw data directly

SCAN Raw Images:

SCAN MRI/PET images will be made available through LONI hopefully starting in summer of 2023.