Cgrid

Cgrid imposes Cartesian grids on selected regions of the human cortical surface to transform folded cortical geometry into rectangular matrices for spatially oriented analysis of surface-based neuroimaging data.

Key Features:

• Cartesian Grid Imposition: Overlays Cartesian grids on selected cortical regions and converts curved cortical surfaces into rectangular matrices.
• Freesurfer Annotation Compatibility: Generates grids based on regions of interest or combinations thereof using Freesurfer's annotation schemes.
• Evaluation on T1-weighted Reconstructions: Was evaluated on surface reconstructions from T1-weighted images of 30 subjects, producing 17 distinct Cgrids that collectively covered nearly the entire cortical surface with a 90.4% generation success rate.
• Facilitation of Spatial Analysis: Provides a structured representation that enhances pattern recognition, supports detailed comparisons between hemispheres, and enables integration of volumetric analyses with surface-based data.
• Output Compatibility with fMRI/MRI Packages: Produces outputs compatible with most existing fMRI/MRI analysis packages and suitable as input for second-level analyses.

Scientific Applications:

• Cortical mapping and localization: Enables cortical mapping by providing a Cartesian coordinate framework for surface-derived measures.
• Pattern recognition across folded cortex: Supports analysis of spatial patterns and improved positional inference on the convoluted cortical surface.
• Interhemispheric comparisons: Facilitates detailed comparisons of surface measures between left and right hemispheres.
• Integration with volumetric and group analyses: Allows integration of surface-based results with volumetric analyses and use in second-level fMRI/MRI group analyses.

Methodology:

Imposes Cartesian grids on cortical surface regions, converts curved surfaces into rectangular matrices, generates grids from Freesurfer annotation-based ROIs using surface reconstructions from T1-weighted images, and produces outputs formatted for compatibility with fMRI/MRI analysis packages.