Preschooler with fever and right facial tenderness Pediatric Imaging Neurological June 25, 2022June 16, 2022 Axial CT with contrast of the brain with bone windows (left) shows complete opacification of the mastoid air cells bilaterally. MRV with contrast of the brain (right) shows a lack of venous flow in the right sigmoid sinus. The diagnosis was acute mastoiditis with thrombosis of the right sigmoid sinus. Related Published June 25, 2022June 16, 2022