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Help & FAQS

If you’re looking for study schedules or documents, visit the Study Documents page.

If you’re looking for details about study cohorts, visit the Background & Rationale page.

If you’re looking for an overview of ADNI and its phases, visit the Study Design page.

If you’re looking for updates on ADNI3, visit the ADNI3 page.

 

Using the Data Archive

The Image & Data Archive (IDA) is a user-friendly environment to archive, search, share, track and obtain ADNI data. A valid user account and an approved ADNI Data Use Application are required to access the ADNI images and data. For more information on obtaining access to ADNI data please review our Access Data page.

User Manual

Review the IDA User Manual to learn how to search, share, download, batch archive, and manage/obtain ADNI data. There are also instructions for logging in and managing users.

Specifications

Internet connection with a web browser and Java Plug-in (Oracle/Sun version) 1.5 or higher. Test if Java is working on your computer.

Data Archive Terms & Codes

If you have questions about the terms or codes used in the ADNI Data Archive, type it in the search above for the ADNI Data Dictionary.

Training Sessions

ADNI provides online data training sessions to introduce users to navigating the data archive, using visualization tools and finding relevant materials on this site or related websites. Sessions are hosted by the ADNI Biostatistics core and will be announced in News section of this site.

ADNI Data Training Slides

ADNI Image Collections Database Instruction

Instructions for ADNI Merge Packages for Windows

Commonly ADNI Used Tables

Common Issues Working with ADNI data

If you are interested in corresponding about a specific data type, contact the respective ADNI Core on the Contact Us webpage.

Freqently Asked Questions

Data
Finding Data

How do I download data?

Investigators wishing to use ADNI data must apply for access and obtain approval from the ADNI DPC. Once approval is received, users may log into the Image and Data Archive to select and download data.  Additional information about using the LONI IDA may be found on the IDA Support page

How do I get the clinical data?

The clinical data set may be downloaded by authorized users only. Please visit the Access Data page for more information.

Where is the data dictionary?

At the top of the ADNI page, a menu bar exists for several types of searches. Click on “data dictionary” and type your query into the search box. The data dictionary for clinical data is also located on the  LONI Image Data Archive (IDA) . Enter your username and password, go to Download, then Study Data. When you click on Study Info, you will see Data Dictionary [ADNI1,GO,2] (DATADIC.csv). Some files will have their own data dictionary, particularly those related to some of the biospecimens and the imaging numeric summaries.

Where can I find a copy of the cognitive assessment worksheets (ADAS-Cog, etc.) used to score patients at each visit?

There are three versions of the ADNI cognitive assessments for ADNI. Unfortunately, we are unable to release the worksheets. Refer to Cognitive Assessment section of the ADNI General Procedures Manual for information regarding cognitive assessments at visits other than BL, M6 and M12.

How can I find images that correspond with the numeric summary files (adni_strokesum, adni_ucbpet, adni_ucsdvol, adni_ucsfsntvol, etc)?

You may find the images in the following ways:

  • The csv files provided in the clinical data downloads contain the subject ID, visit code and unique LONI image ID for each value reported.
  • Use these elements to searchthe IDA. Specifically, enter the subject ID, choose the appropriate visit code and select processed data (radio button).
  • On the query results page, hold the mouse over the series description to determine the LONI image ID (the URL shown at the bottom of the web browser contains the imageId that matches that in the csv files).

Are any atlases available for the data (ie an AD atlas)?

Not at this time.

How are patients who transitioned from normal to MCI or MCI to AD identified?

Diagnosis conversion information is captured in the “Diagnostic Summary” data set which may be downloaded from within the ADNI Data Archive.

Where is the “EXAMDATE” in clinical data?

Not all clinical data files contain date of the exam (EXAMDATE) especially for ADNIGO/2. You can extract EXAMDATE from the registry table (REGISTRY.csv) using RID, Phase, and VISCODE.

Where is the data dictionary?

The data dictionary for clinical data is located on the LONI Image Data Archive (IDA). Enter your username and password, go to Download, then Study Data. When you click on Study Info, you will see Data Dictionary [ADNI1,GO,2] (DATADIC.csv). Some files will have their own data dictionary, particularly those related to some of the biospecimens and the imaging numeric summaries.

ADNI2 VISCODE is different from ADNI1 and ADNIGO. How can I make use of visit codes across the three phases of ADNI?

ADCS created a new visit code variable called “VISCODE2” (sc, scmri, bl, m06, etc.) for ADNI2. (Please see ADNI 2 Visit Codes Assignment Methods (PDF) on LONI). For longitudinal models, it is still recommended that people use the actual time since the initial visit (using EXAMDATE) rather than the visit code to determine time, because there is variability in when the visits occurred.

How do I determine the eMCI subjects in ADNIGO and ADNI2?

Early MCI (eMCI) subjects were added to the recruitment in ADNIGO and ADNI2 to get some MCI subjects earlier in the course of 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.

Interpreting Data

How is missing data coded in the datasets?

Missing data is coded with -1 and -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.

What is the difference between screening and baseline scans? Why the distinction?

This is mostly answered on the image-data page.  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.  A chart detailing imaging visits is show in the Image Data section.

Why do certain groups have data missing at certain steps (ie only MCI data at month 18)?

The study design specifies the visits required for each research group (Control, eMCI, MCI, AD). You can review the study schedule in the procedures manual for ADNI1, ADNI GO, or ADNI2 or download the study schedule. These documents can be found on the Documents: Procedures, Protocols, and Manuals webpage.

Which column in all the CSV files is the ADNI subject ID number correspondent to the “Subject ID” number in the LONI-ADNI database, the “ID” column or the “RID” column?

In the ADNI subject IDs of the form 123_S_5678, the last 4 digits correspond to the roster ID (RID) which you see in every CSV file. You can also refer to the ROSTER table which lists RIDs and their associated PTIDs (of the form 123_S_5678).

What is the meaning of the visit identifier “Not Yet Determined” (NV)?

The NV (“No Visit” or “Not Yet Determined”) visit code is applied when we receive 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.

How are the ADAS cognitive tests scored?

The Alzheimer’s Disease Assessment Scale was devised to evaluate cognitive impairment in the assessment of Alzheimer’s disease. ADAS-Cog is recommended for second stage or more detailed assessments and/or for particular research evaluations rather than for applications in routine care settings.

What is the difference between the baseline diagnosis and the screening 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. The diagnosis at the screening diagnosis was used to randomize individuals to an arm of the ADNI-1 study (1.5T only, 1.5T + 3T, 1.5T + FDG-PET), but 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.

You can extract the baseline diagnosis from LONI Download Study Data > Diagnosis > Diagnosis Summary [ADNI1, GO, 2] (DXSUM_PDXCONV_ADNIALL.csv). 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.

What is the difference between cross-sectional and longitudinal FreeSurfer?

 

FreeSurfer can measure volume of cortical or subcortical structures and compute cortical thicknesses using cross-sectional and longitudinal processing. Longitudinal processing creates within a subject template and initializes each time point with the template to reduce individual variability. The 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/2 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).


Why are abeta, tau values different for VISCODE=bl in the different biomarker files?

Specimens from the same subject at the same time point will have slightly different test values if they are tested 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.

Where are the training/test set assignments that can be used for cross-validation?

You can download the Cross-Validation training set from the Download | Study Data section of the ADNI data repository (https://ida.loni.usc.edu).

How do I determine the 819 individuals officially enrolled in ADNI-1?

Using “REGISTRY.csv,” we have 822 subjects with initial screening (VISCODE == ‘sc’), but only 819 subjects had baseline visit conducted (VISCODE == ‘bl’ and RGCONDCT == 1 (RGCONDCT: Was this visit conducted? 1=Yes, 0=No)). Three people were deemed ineligible after the screening visit and were therefore not continued on to the baseline visit. The 819 that had a baseline visit are considered the official ADNI1 sample.

User Account

How do I add co-investigators and research assistants so they can access ADNI data?

  1. After you log in to your account, click on “My Account” in the upper right corner.
  2. In the Project line “ADNI” click the “Update” button.
  3. Click the “Co-Investigator Update” Tab to review your co-investigators.
  4. Click “Add Investigator” and enter their information.
  5. Click “Add User” when your are done.
  6. When you have entered all of your co-investigators, click “Update”. They will be sent a confirmation email with information about logging in to the ADNI data archive.

How do I submit a manuscript for review?

  1. After you login, click “My Account”  in the upper right corner.
  2. Click the “Update” button, in the Project line for ADNI
  3. On the ADNI User Account Update webpage, select the “Publication Update” Tab
  4. Enter and upload your publication information
  5. Email your manuscript to the DPC, EDRAKE@BWH.HARVARD.EDU
Submitting a manuscript is a requirement of the ADNI data use agreement.

How do I download data?

If you are a new user, we suggest first consulting the LONI Image Data Archive User Manual, which provides step-by-step instructions about the Data Archive online system.

What is the current status of our application?

It takes approximately 1 week for your application to be approved. The online application form must be fully completed and include the investigator’s institutional affiliation and the proposed research to be conducted using ADNI data. In case you made an error, you can resubmit your application for ADNI Data. Specific inquiries can be directed to the ADNI Data Sharing and Publications Committee (DPC).

I cannot access my account

Part of the ADNI Data Use Agreement requires that you update your proposed analysis on an annual basis in order to keep your account activated. We send an email reminder a few weeks prior. If you fail to comply, your account will be deactivated. You may need to reactivate your account or reapply for data access. Contact the DPC to re-evaluate your account access.

Another possibility is that you may need to recover your password, see next entry.

I forgot my password

Click here to recover your password and access your Data Archive Account.

What are the IDA System Requirements?

The basic requirements are:

Study

What’s the difference between the ADNI 1, ADNI GO, ADNI 2 and ADNI 3 studies?

Although the four studies 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. For instance, DTI data is available from some ADNI GO and ADNI 2 subjects, as this is fairly new technology. ADNI manuals, procedures are protocols from each study are available on the  ADNI Documents: Procedures, Protocols, and Manuals webpage for download. Visit the ADNI 3 page to learn more about what’s new in ADNI 3.

How can I acknowledge/cite the ADNI data/protocols?

Acknowledgement requirements are detailed in the Data Sharing and Publications Policy. This and other relevant documents can be found on the webpage, “How to Apply for Data“.

Where can I sign up for a Clinical Test?

Please visit the Alzheimer’s Disease Education and Referral (ADEAR) Center Website for a listing of open clinical studies. You can sign up at one of our acquisition site locations, in the US or Canada. Browse our map on the Study Site page.

What is a Biomarker?

A biomarker, or biological marker, is a substance, measurement or indicator of a biological state. Biomarkers may exist before clinical symptoms arise. ADNI uses various biomarkers to help predict the onslaught of Alzheimer’s disease. Read more about biomarkers on the study Background & Rationale webpage.

I’d like to interview ADNI for the Press. Who can I contact?

Mike Weiner is the principle investigator of ADNI. Read his bio and get his contact information from the Administrative Core webpage.

Ask the Experts

EXPERT KNOWLEDGE BASE
Clinical Core Q&A