Version 4.1 of the IIT Human Brain Atlas was released on 10/15/2015. The new version includes several improvements, few bug-fixes, and several new files, mainly related to the white matter atlas. New HOW-TO documents have also been added to the "Docs" section. The most important changes are the following:
i) The previous version of the white matter atlas included information for the top 20 most probable fiber connections per voxel. The top 20 most probable connections did not provide enough information and reduced the accuracy of edge density maps, especially in the posterior portion of the brain. The new version provides information for the top 60 most probable fiber connections per voxel, which addresses the problem with edge density maps.
ii) The white matter atlas and confidence maps are now available in two formats: a) a 4D file containing 60 3D volumes, and b) 60 separate files each containing a 3D volume.
iii) A bug has been fixed in regionstat.m. The bug led to lower probabilities that a fiber passing through a voxel of an ROI belongs to a certain connection.
iv) A bug in the major fiber bundles files files has been corrected (affecting the corticospinal tract and the fornix).
v) A HOW-TO document that explains how to use the IIT white matter atlas to find the connections of a gray matter label to other gray matter labels has been added.
vi) A HOW-TO document that explains how to display in color the most probable white matter connection in each voxel of the IIT Human Brain Atlas has been added.
vii) A look-up table that allows visualization in color of the most probable white matter connection in each voxel of the atlas has been added.
viii) All HOW-TO documents have been updated.
A description of the new files that have been added to the white matter atlas can be found in the "Contents_of_IIT_atlas_v4.1" document in the "Docs" section.