Toward standardizing spatial analysis for optical topography

Optical topography is an emerging neuroimaging technique for the noninvasive monitoring of human cerebral hemodynamics. Its relatively more compact, flexible, and affordable setup allows bedside monitoring of patients and infants in clinical situations, and of healthy subjects in their real-life environments. However, optical topography poses a technical obstacle in that it measures cortical activities from the head surface without anatomical information of the brain, which is essential to identify the source of the monitored brain activity. It also poses difficulty in comparing data with that from other neuroimaging techniques, which use a standard template for presenting functional brain analyses. To cope with this problem, we have developed spatial analysis methods that allow stand-alone optical topography data to be presented in standard brain spaces. These methods are automatic and do not require the subjects´ MR images, which may be too expensive or difficult to acquire under certain clinical or experimental restrictions.