“…Surfacebased methods have identifi ed that areas of focal cortical dysplasia can be preferentially located at the bottom of abnormally deep sulci (Besson, Andermann, Dubeau, & Bernasconi, 2008 ), a fi nding which may be used to direct the search for developmental abnormalities, particularly when MRI features are only mildly abnormal or absent. Uniquely, surface-based methods can characterize subtle surface features, such as cortical thickening, blurred gray-white matter boundary, and hyperintense T1 signal (Besson, Bernasconi, Colliot, Evans, & Bernasconi, 2008 ). These characteristic features, particularly in combination, can be used to detect subtle abnormalities that escape visual detection.…”