Defining the human hypothalamus in vivo by ultra-high field 7 Tesla MRI

Introduction: Post mortem studies have shown a volume deficit of the hypothalamus in depressive patients. With ultra-high field (7 Tesla) MRI this effect can now be investigated in vivo in detail. But to benefit from the sub-millimeter resolution a segmentation procedure was required that overcomes limitations of existing procedures, in particular schematic approximations. Methods: Using 7 Tesla T1 images the traditional anatomical landmarks of the hypothalamus were refined. A detailed segmentation algorithm (unilateral hypothalamus) was developed for colour coded, histogram-matched images and evaluated in a sam…