Add Primer On Output Data Types (cut from ABCC RTDs)

[LuciMoore]

Primer On Output Data Types

Derivatives follow standards defined by the Human Connectome Project, such as reporting different metrics in standard grayordinate space and saving data using CIFTI standard file formats. A couple of great blog posts to check out for more in-depth information on CIFTI data types include:

• NIfTI, CIFTI, GIFTI in the HCP and Workbench: a primer by Jo Etzel from Washington University in St. Louis
• A layman’s guide to working with CIFTI files by Mandy Mejia from Indiana University

The following data types, listed by file name extension, are available in this collection's BIDS derivatives.

.dlabel.nii: "Dense label files" contain the "labels" (a.k.a. parcels) within parcellations.
.dscalar.nii: "Dense scalar files" contain cortical thickness, curvature, and myelin maps on a scalar value per surface vertex basis.
.dtseries.nii: "Dense time series" contain functional time series from fMRI runs in surface space on a vector time series per surface vertex basis.
.ptseries.nii: "Parcellated time series," contain the dense time series parcellated by the corresponding dense label file.
.surf.gii: "GIFTI surface files" contain the "geometry" surface delineations/definitions of a particular surface, like the midthickness surface for example.