OASIS volume based morphometry maps

Access

See nilearn.datasets.fetch_oasis_vbm.

Content

‘gray_matter_maps’:

Nifti images with gray matter density probability

‘white_matter_maps’:

Nifti images with white matter density probability maps

‘ext_vars’:

Behavioral information on the participants

‘data_usage_agreement’:

Text file containing the data usage agreement

Notes

The Open Access Structural Imaging Series (OASIS) is a project dedicated to making brain imaging data openly available to the public.

OASIS is made available by the Washington University Alzheimer’s Disease Research Center, Dr. Randy Buckner at the Howard Hughes Medical Institute (HHMI) at Harvard University, the Neuroinformatics Research Group (NRG) at Washington University School of Medicine, and the Biomedical Informatics Research Network (BIRN).

Data Usage Agreement

Using data available through the OASIS project requires agreeing with the Data Usage Agreement that can be found at https://sites.wustl.edu/oasisbrains/

In the DARTEL version, original Oasis data have been preprocessed with the following steps:

1. Dimension swapping (technically required for subsequent steps)

2. Brain Extraction

3. Segmentation with SPM8

4. Normalization using DARTEL algorithm

5. Modulation

6. Replacement of NaN values with 0 in gray/white matter density maps.

7. Resampling to reduce shape and make it correspond to the shape of the non-DARTEL data (fetched with dartel_version=False).

8. Replacement of values < 1e-4 with zeros to reduce the file size.

In the non-DARTEL version, the following steps have been performed instead:

1. Dimension swapping (technically required for subsequent steps)

2. Brain Extraction

3. Segmentation and normalization to a template with SPM8

4. Modulation

5. Replacement of NaN values with 0 in gray/white matter density maps.

An archive containing the gray and white matter density probability maps for the 416 available subjects is provided. Gross outliers are removed and filtered by this data fetcher (DARTEL: 13 outliers; non-DARTEL: 1 outlier) Externals variates (age, gender, estimated intracranial volume, years of education, socioeconomic status, dementia score) are provided in a CSV file that is a copy of the original Oasis CSV file. The current downloader loads the CSV file and keeps only the lines corresponding to the subjects that are actually demanded.

For more information this dataset’s structure: https://sites.wustl.edu/oasisbrains/, Open Access Series of Imaging Studies (OASIS)[1], and Marcus et al.[2].

References

[1]

Open access series of imaging studies (oasis). https://sites.wustl.edu/oasisbrains/. Accessed: 2021-05-19.

[2]

Daniel S. Marcus, Tracy H. Wang, Jamie Parker, John G. Csernansky, John C. Morris, and Randy L. Buckner. Open Access Series of Imaging Studies (OASIS): Cross-sectional MRI Data in Young, Middle Aged, Nondemented, and Demented Older Adults. Journal of Cognitive Neuroscience, 19(9):1498–1507, 09 2007. doi:10.1162/jocn.2007.19.9.1498.

License

Provided under an open access data use agreement (DUA).