Example CT image slice of area with widest frontal horns in (a) a normal subject and (b) a subject diagnosed with NPH. (c) and (d) are masks overlaid on the original image indicating the ventricles (red), gray-white matter (green), and subarachnoid space (blue). In this example, the width of the frontal horns appear similar in the normal subject and the NPH subject, but the total volume of the ventricles differs. This is one example of a case where 3D volumetric measurements may be helpful in differentiating potential patients with NPH from those without NPH. These annotations are carefully created from the 3D data and are available to the public.