Drost WT, Berry CR, Fisher PE.
A nine-year-old German Shepherd dog presented to the Veterinary Teaching Hospital at North Carolina State University with an eleven-day history of progressive depression, lethargy, inability to walk, blindness and intermittent vomiting. Computed tomography (CT) of the brain was unremarkable; however, bilateral regions of low photon absorption were noted within the tentorium cerebelli osseum. Mean CT numbers of -47.9 Hounsfield units (HU) and -26.4 HU were recorded within the left and right areas, respectively. These areas most likely represent diploÎ and are presumably a normal variant of the canine skull. A possible explanation for this finding includes a developmental variant where the medial and lateral plates of the tentorium cerebelli osseum fail to fuse, thus leaving a space for diploÎ accumulation. Use of various combinations of CT windows and numbers can be valuable for characterizing such variants.