ADNI data is centrally stored in the Laboratory of Neuroimaging (LONI) Image & Data Archive (IDA). Investigators interested in downloading ADNI data may apply for access here.
The ADNI clinical data set may be downloaded by authorized and approved users only. Please visit the Access Data page for more information.
The data dictionary is located in the Study Data section of the LONI Image Data Archive (IDA) and in the ADNI website data dictionary page. Log in to the IDA, select study as ADNI → Download → Study Data. The primary data dictionary file can be found in the Study info → Data & Database section of the Study data page. Certain files will have their own data dictionaries, particularly those related to some of the biospecimens and the imaging numeric summaries.
Unfortunately, we are unable to release the worksheets. Please refer to Cognitive Assessment section of the ADNI Procedures Manual (specific to each phase of ADNI) for information regarding cognitive assessments. These documents can be found on the ADNI Documentation page.
Per the ADNI Data Use Agreement, users acknowledge that all data is preliminary and the user is responsible for checking the IDA for data updates. Data from the ADNI electronic data capture system (EDC) is updated daily. Analysis or assessment datasets are updated in the IDA as they are completed by the investigating laboratories and an ADNI news posting is released to ADNI news subscribers. Users may subscribe to receive ADNI news postings here.
Please review the ADNI Imaging files located in the DOWNLOAD → Study Data → Imaging section of the ADNI repository. The tables here contain information relevant to the DICOM files, which may include specific scanner and protocol information.
Please review the Schedule of Events in the ADNI Protocols (specific to each phase of the ADNI study) located on the ADNI Documentation page. Study dates are available for reconciliation between MR and PET acquisitions.
The CSV files provided in the clinical data downloads contain the subject ID, visit code and unique LONI IMAGEID for each value reported. These values can be used to search the IDA image repository for the associated images.
There are currently no atlases available for the data.
Missing data can be coded in a number of ways, and may vary between tables as well as between phases. In some cases missing data iscoded as -1 or -4. Generally, -4 is used for “passively” missing or not applicable (e.g. item is not collected at a particular visit), and -1 is used for data which is confirmed missing at point of data entry. Missing data can also present as NA entries, empty strings, 0’’s, and combinations of these schemes.
The study design specifies the visits required for each research group (CN, MCI, AD/DEM). Please review the study schedule in the Procedures Manual for ADNI1, ADNI GO, ADNI2, ADNI3 or ADNI4. These documents can be found on the ADNI Documentation page.
New participants are initially assessed at a ‘screening’ visit and if not excluded (due to inclusion/exclusion criteria or lost to follow-up), they will move to a ‘baseline’ visit to complete additional assessments/study tasks.
FOR SCREENING/BASELINE DIAGNOSIS: The screening visit consists of a subset of the planned assessments (neuropsychological testing, imaging, etc.) sufficient to evaluate the inclusion/exclusion criteria for each potential participant. Once a participant passed screening, the baseline assessment was conducted in which additional neuropsychological testing, imaging, and fluid samples were taken. Note that the diagnosis from the baseline visit is considered more accurate. For most individuals, the two diagnoses are the same, but the diagnosis did change for a handful of subjects. In some phases of the study, the diagnosis at the screening visit was used to randomize individuals to an arm of the ADNI1 study (such as related to imaging: 1.5T only, 1.5T + 3T, 1.5T + FDG-PET). The baseline diagnosis can be extracted from IDA → Download → Study Data → Diagnosis → Diagnosis Summary [ADNI1, GO, 2, 3, 4]. ADNI1 baseline diagnosis can be obtained using the “DXCURREN” variable at VISCODE==”bl,” ADNIGO/2 baseline diagnoses can be obtained using the “DXCHANGE” variable, and ADNI3 baseline diagnosis can be obtained using the “DIAGNOSIS” variable.
FOR SCREENING/BASELINE SCANS: A chart detailing imaging visits is shown in the Image Data section. Further explanation could be — (ADNI 1): Subjects who were randomized into the 3T scanner group had a 1.5T screening scan as part of the study inclusion/exclusion screening. Those subjects meeting inclusion criteria had a 3T scan at the Baseline visit.
Please refer to the ROSTER file located in the Download → Study Data → Enrollment section of the ADNI repository. This file contains the link between the RID and PTID. The last 4 or 5 digits of the imaging data Subject_ID correspond to the RID which you see in every CSV file.
Please refer to the Diagnostic Summary file located in the Download → Study Data → Assessments section of the ADNI repository. The variable DXCHANGE can be used to identify the different diagnostic groups. The Data Dictionary file contains the coding for this variable. The ADNIMERGE file (ADNIMERGE – Key ADNI tables merged into one table [ADNI1,GO,2,3], which can also be found on the Study Data page) has combined all the diagnosis information from the various variables in the Diagnostic Summary file to give the participant’s diagnosis at each visit, which might also be helpful.
For information about how diagnostic status is assessed, please refer to the relevant sections of the ADNI procedures manuals for each phase on the ADNI Documentation page.
For longitudinal analysis, it is recommended that you use the actual time since the initial visit (using EXAMDATE or VISDATE) rather than the visit code to determine time as there is variability in when the visits occurred.
For the purposes of merging tables, VISCODEs are phase-specific, and should always be used in conjunction with another field indicating the phase of ADNI associated with the viscode.
Early MCI (eMCI) subjects were added to the recruitment in ADNIGO and ADNI2 to get some MCI subjects earlier during their impairment. These individuals still have a diagnosis of MCI but have less memory impairment than the MCI subjects recruited during ADNI1 (Late MCI or lMCI). ADNIGO and ADNI2 will continue to recruit subjects in the lMCI category. You can identify the eMCI subjects by merging the ARM table with the Diagnostic Summary table and identifying those with ARM==10 & DXCHANGE==2.
FreeSurfer can measure the volume of cortical or subcortical structures and compute cortical thicknesses using cross-sectional and longitudinal processing. Longitudinal processing creates a within-subject template and initializes each time point with the template to reduce individual variability. ADNI1 images have been processed both cross-sectionally and longitudinally up to time point 9. ADNIGO/ADNI2 images have been processed using cross-sectional FreeSurfer, and are being processed using Longitudinal FreeSurfer for subjects with at least 2 time points within 1 year. ADNIGO/ADNI2 longitudinal data will be processed to track longer-term changes as data accumulates. If the researcher is interested in baseline values and their association with some longitudinal or cross-sectional outcome, we recommend using cross-sectional FreeSurfer values. If interest lies in longitudinal change in the volumes or cortical thicknesses, the longitudinal version of FreeSurfer is recommended (when restricting to ADNI1 subjects).
Specimens from the same subject at the same time point will have slightly different test values if they are analyzed at different times. To minimize differences due to different assays, when a new batch of samples is run from later visits, samples from earlier visits are also included. Therefore, each biomarker file contains values from all samples run in the same batch and researchers should only use values within the same file.
The NV (“No Visit” or “Not Yet Determined”) visit code is applied when we receive imaging scan QC data (e.g., mrinclusio) before we receive scan information sheets (e.g., mrimeta). In these instances, we do not yet know with which visit the scan QC data is associated. Occasionally scan QC and scan information records which should be linked are not linkable because of discrepant data (e.g., exam dates do not match). The NV data code will be used in these cases as well, until the discrepancies are corrected.
Yes, a manuscript submission to ADNI is required. Please refer to and follow the terms of the ADNI Data Use Agreement and ensure that your manuscript complies with the ADNI Data Sharing and Publication Policy. As a reminder, any manuscript that uses ADNI data must be sent to the ADNI DPC, include ADNI in the author line, and use specific ADNI language in the methods and acknowledgement sections.
Follow the steps below to submit a manuscript in the IDA:
After you submit your manuscript, please allow the ADNI DPC up to 2 weeks to review your manuscript. Again, the review is for administrative purposes to ensure that ADNI is cited appropriately. For questions related to manuscript review status, please contact the ADNI DPC Coordinator.
Continued access to the ADNI database requires online submission of an annual progress report. When the progress report is not received in the allotted time, access to the ADNI data expires. Please contact the ADNI DPC Coordinator for further information and options.
On the IDA homepage, click ‘Log In’ in the upper right-hand corner of the page. Then click“Forgot Password?” and follow the three step process to reset your password.
The basic requirements are:
It takes approximately 2 weeks for your application to be approved. The online application form must be fully completed. In case you made an error, you can resubmit your application for ADNI Data. Specific inquiries can be directed to the ADNI DPC Coordinator.
Please log into the IDA website and select ‘My Account’ in the upper right-hand corner of the page. Under the “Data Use” section, select the ‘Update’ button for the ADNI study and you can provide the required information for your update.
Once you have received access, you can add the co-investigators by following these steps:
To update your email account in IDA, please follow these steps:
You should receive an email with a security code, which will be required to complete the update process.
Unfortunately, it is not possible to transfer the data access to another investigator. The original PI will need to cancel their account for this study and the new PI should re-apply to the study as the PI.
Steps to cancel account:
The ADNI news can be found here in the ADNI News page.
If you haven’t already done so, you may be interested in signing up for email notifications of the ADNI news postings. Please click the ‘Subscribe to ADNI News’ link on this page, and you will receive an email notification when new ADNI data sets are available for download on the IDA.
Although the five phases of ADNI all aim to advance AD research, you will find differences in participant pools, and adjustments to data collection protocols over time as a result of scientific findings and changing technologies. These differences are outlined in the Study Objectives and the Data & Samples sections for each core. ADNI manuals, procedures are protocols from each study are available on the ADNI Documentation page for download.
Acknowledgement requirements are detailed in the Data Sharing and Publications Policy. This and other relevant documents can be found on the ADNI Access Data page.
Please visit https://www.adni4.org for more information about participating in the current phase of the ADNI study.
Please contact the principal investigator of ADNI, Michael W. Weiner, MD.
MR vendors now apply their own pre-processing steps as part of the product, prompting ADNI to not perform its own pre-processing on images for ADNIs 3 and 4. ADNIs 1, and the initial parts of ADNI2/GO images were captured prior to vendor-initiated pre-processing, so the MRI Core provided intensity normalized and gradient un-warped T1 image volumes during these ADNIs. Later in ADNI2/GO, these corrections were applied on the scanner at the time of image reconstruction when these had been implemented in the vendor product.
For ADNI4 data, it is recommended to use the “chosen” series selected during the QC process. Every series in every scan undergoes quality control at the Mayo ADIR Lab which includes selecting the “best” series if duplicate acquisition of that series was uploaded from the site. If the interest is in previous ADNIs, researchers may find a benefit from selecting the MPRAGE files for the highest quality ratings. Furthermore, imaging files are available at every stage of pre- and post-processing where applicable, and researchers are encouraged to utilize the detailed search functions when searching for and downloading images to suit their particular needs.
Paper protocols for all phases of ADNI can be found here
Although efforts are made to create similar naming conventions across vendors there is an innate difference between certain sequence names from different vendors. For example, a 3D T1 scan may be called an MPRAGE for Siemens and Philips, however, until recently, GE’s version of T1 was named IR-SPGR. Users should not rely solely on series naming conventions but look at the information located in the images DICOM header to determine exact parameters.
No, field mapping is not acquired in any ADNI4 scanner manufacturers. No other additional field maps are created/offered by ADNI our recommendation would be to use the Vendor products for field mapping/corrections.
The ADNI4 protocol includes a localizer, 3D T1, 3D FLAIR, 3D T2, T2 GRE, DTI, ASL, rsfMRI, and a High-Resolution Hippocampus scan. Spatial resolution for the 3D T1, 3D FLAIR, and 3D T2 series are all 1mm cubed. Please see ( ) for a more detailed description of the scans included in this protocol. A considerable effort was made to ensure harmonization across all available ADNI4 data regardless of scanner type, participant, and timepoints. However, the ADNI4 protocol has unique characteristics included compared to previous ADNI protocols, so care should be given when comparing data across ADNI iterations.
This information can most reliably be found in the DICOM headers of the fMRI acquisition. In addition, some of this information can be found in the NFQ data analysis provided for users located here: IDA
No, the fMRI performed in ADNI is intended to be a task-free resting state fMRI. Participants are only instructed to keep their eyes open during the fMRI sequence to ensure they are not sleeping during the acquisition and to achieve as uniform a functional state as possible across scans.
As with all sequences acquired, detailed information can most reliably be found in the DICOM headers of the acquisition. The protocol descriptions ( ) provide general parameter information for each series type by vendor platform. Information about diffusion analysis methods, including DTI, can be found at LONI: IDA
ADNI recommends that the main diffusion sequence be acquired with a P->A acquisition, unless you have a particular interest in the brainstem, in which case you should use A->P For many scanners ADNI also acquires a short A->P scan to support an optional correction step for EPI distortion. Note that newer GE scanners (ADNI4) include correction of EPI distortion in their reconstructions.
ADNI recommends a 2x2x2 voxel size.
This depends on the available scan time and/or whether the scanner is capable of 3x slice acceleration. At a minimum, ADNI recommends b = 0 and 1000 s/mm2 values be acquired, but for systems with multislice acceleration capability it also acquires b = 500 and 2000 s/mm2 shells, using custom diffusion vector sets. Acquiring multiple b shells enables analysis methods beyond DTI in order to more specifically separate microstructural changes from macrostructural ones (partial volume contamination of voxels by CSF due to atrophy).
MR vendors now apply their own pre-processing steps as part of the product, prompting ADNI to not perform its own pre-processing on images for ADNIs 3 and 4. ADNIs 1, and the initial parts of ADNI2/GO images were captured prior to vendor-initiated pre-processing, so the MRI Core provided intensity normalized and gradient un-warped T1 image volumes during these ADNIs. Later in ADNI2/GO, these corrections were applied on the scanner at the time of image reconstruction when these had been implemented in the vendor product.
ADNI has based their ASL sequence on recommendations from the “ISMRM White Paper”.
ADNI has found that 2D ASL imaging is by far inferior to 3D ASL imaging and has made the decision to no longer acquire 2D ASL data moving forward.
If you are 55 to 90 years of age you may be able to participate. Participation is free and no medication is involved.
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