There are 3 OASIS datasets that can be viewed and downloaded on XNAT Central. The data from these projects should not be combined - Each dataset should not be used individually only, as there may be overlap across the different studies.
OASIS-1 consists of cross-sectional MRI data from 434 scan sessions across 416 different subjects. It was made available in 2007.
OASIS-2 consists of longitudinal MRI data from 373 scan sessions across 150 subjects. It was made available in 2010.
OASIS-3 consists of both cross-sectional and longitudinal MRI and PET data across 1098 subjects. It was made available in 2018.
OASIS data can be downloaded via the using scripts called from a Windows, Mac, or Linux command line. This can be useful if you'd like to use scripts to automate downloading or organize files.
For a sample script to download individual MR scans from XNAT Centralexample scripts and instructions on how to use them, visit the oasis-scripts repository on Github.
Creating Usable Spreadsheets for Downloading Data
The example OASIS download scripts on the Github page require a list of OASIS subjects as an input. This can be created by including the "Subject" column in your column view, and downloading the result via the Options → Spreadsheet option described above. Once you download a spreadsheet, remove all columns from it except for the "Subject" column and save it as a .csv file. This can be done In Microsoft Excel by selecting Save As and choosing "CSV (Comma delimited) *.csv" as the file type.
If you save a file using Microsoft Excel, you must convert it to Unix format before using it as input to a script. If the file is incorrectly formatted, you will receive "Illegal character" errors when you run the script. Instructions for doing this conversion can be found in the "Note on Unix file formatting" section of the oasis-scripts README.
Writing Custom Scripts Using the REST API
More advanced users can write their own scripts to download data from XNAT Central via the REST API. For more details on using the XNAT REST API to download scan data and processed image data, see How To Download Files via the XNAT REST API.