What can we learn from T2* maps of the cortex?
Studies have shown that T2* contrast can reveal features of cortical anatomy. However, understanding the relationship between T2* contrast and the underlying cyto- and myelo-architecture is not an easy task, given the number of confounds, such as myelin, iron, blood vessels and structure orientation. Moreover, it is difficult to obtain reliable T2* measurements in the cortex due to its thin and folded geometry and the presence of artifacts. This review addresses issues associated with T2* mapping in the human cortex. After describing the theory behind T2* relaxation, a list of practical steps is proposed to reliably acquire and process T2* data and then map these values within the cortex using surface-based analysis. The last section addresses the question: "What can we gain from T2* cortical mapping?", with particular emphasis on Brodmann mapping.
Institute of Biomedical Engineering, Ecole Polytechnique de Montreal, QC, Canada; A.A. Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA, USA. Electronic address: jcohen@polymtl.ca.
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D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging
Biomarker; Brodmann; Cortex; Cytoarchitecture; Myeloarchitecture; T(2)*