Eyal Lotan MD, MSc, Presenter: Nothing to Disclose

Daniel Barazany PhD, Abstract Co-Author: Nothing to Disclose

Ido Tavor, Abstract Co-Author: Nothing to Disclose

Shani Ben-Amitai, Abstract Co-Author: Nothing to Disclose

Gahl Greenberg, Abstract Co-Author: Nothing to Disclose

Galia Tsarfaty MPH, Abstract Co-Author: Nothing to Disclose

Chen Chaim Hoffmann MD, Abstract Co-Author: Nothing to Disclose

David Tanne MD, Abstract Co-Author: Nothing to Disclose

Yaniv Assaf, Abstract Co-Author: Nothing to Disclose

We have recently showed that inversion recovery (IR) MRI can be used to segment the cortex into laminar shape clusters that represent cortical layers (i.e., IR-layers) in vivo and in 3D. The separation to clusters was done based on their T1 characteristics. In this study, we investigated whether the fronto-parietal neuroanatomical areas can be distinguished based on their IR-layer composition. 

On a 3.0T-MRI, healthy subjects (n=15) underwent high resolution multiple IR-MRI scans in the axial plane covering the fronto-parietal cortex. The inversion time was varied as following: 230, 432, 575, 665, 760, 920 and 1080ms. An anatomical SPGR image was acquired 1mm isotropically covering the whole brain. SPGR was analyzed using Freesurfer framework, to define the brain neuroanatomical areas. Overall 22 fronto-parietal cortical areas were selected based on their representation of the IR-MRI coverage (11 areas in each hemisphere, minimum of 10000 voxels in each area). The IR-MRI data was analyzed by Hierarchical Clustering Analysis (HCA), where a dendrogram of the IR layers among all cortical areas was computed using correlation metric scheme to quantify their similarity. 

The multi IR-MRI images were analyzed using a multi-spectral clustering framework revealing distinct laminar shape clusters across the cortex. The analysis was able to define 5 significant similar and consistent IR layers. The dendrogram plot showed that the IR layer composition of homologous areas (i.e., matched areas of the left and right hemispheres), were the most similar. In addition, several areas were found to have shared IR-layer composition.

The IR-layer reflects the tissue microstructure, and therefore can be used as a tool for brain segmentation. We found that homologous areas in both hemispheres have similar compositions, different from other neuroanatomical areas that show distinct composition. 

IR-MRI is a powerful tool that should be combined with traditional measurements for discrimination of cyto-architectonic areas.

Lotan, E, Barazany, D, Tavor, I, Ben-Amitai, S, Greenberg, G, Tsarfaty, G, Hoffmann, C, Tanne, D, Assaf, Y, Fronto-Parietal Cortical Parcellation Using High Resolution Inversion Recovery MRI.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14003760.html