Description of USCBrain atlas
The USCBrain atlas is a new high-resolution single-subject atlas, constructed using both anatomical and functional information to guide the parcellation of the cortex. Individual structural scans can be registered to this atlas using BrainSuite. We also provide uncertainty maps that give probabilistic parcellations.
A high-resolution 3D MPRAGE scan (TE=4.33 ms; TR=2070 ms; TI=1100ms; flip angle=12 degrees; resolution=0.547×0.547×0.802 mm) was acquired on a 3T Siemens MAGNETOM Tim Trio using a 32-channel head coil. Data were acquired 5 times and averaged. The subject is a typical right-handed woman in her mid-thirties with a brachiocephalic brain and no rare anomalies.
Preprocessing and labeling of the MPRAGE image was performed using BrainSuite [1,2]. This MRI volume was used to generate the BCI-DNI atlas as described here.
Functional subparcellations of the gyral ROIs were then generated from 40 minimally preprocessed rfMRI datasets from the Human connectome database . Gyral ROIs were transferred from the BCI-DNI atlas to the 40 subjects using the HCP gray-ordinate space as a reference. For each subject, each gyral ROI was subdivided using the rfMRI data by applying the normalized cuts spectral clustering algorithm to a similarity matrix computed from the correlation between voxels . The number of subdivisions was chosen based on a Silhouette analysis . The subparcellations were then transferred back to the original cortical mesh to create the USCBrain atlas with a total of 65 cortical regions per hemisphere. Probabilistic map of the subdivisions was generated by measuring agreement of the subdivisions across the 40 subjects . The probability maps are stored in .mod files.
The USCBrain atlas can be used with BrainSuite, FreeSurfer and FSL softwares.
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