Pediatric Sinusitis Etiology: bacterial infection of the paranasal sinusesImaging: sinus can have mucosal thickening, air fluid levels, complete opacification, bony destructionComplications: orbital cellulitis, sinogenic abscess Radiology Cases of Sinusitis Waters radiograph of the sinuses shows mucosal thickening and opacification of the bilateral maxillary sinuses, left greater than right. Axial T2 MRI of the brain (above left) shows a mass in the right front lobe with surrounding vasogenic edema. Axial (above right) and coronal (below right) T1 MRI with contrast shows the mass to have thin rim enhancement and the coronal image also shows left maxillary sinusitis. The mass is shown to demonstrate diffusion restriction on diffusion-weighted imaging (below left). Sagittal CT with contrast of the brain shows frontal and left maxillary sinusitis and extensive soft tissue swelling anterior to the forehead (upper left) and destruction of the anterior left frontal bone in the frontal sinus and extensive soft tissue swelling anterior to the left orbit (upper right). Coronal (lower left) and sagittal (lower right) T1 MRI with contrast of the brain shows diffuse meningeal enhancement, subdural empyemas along the falx and both cerebral convexities, and multiple large non-enhancing subgaleal fluid collections in the left scalp. Axial CT with contrast of the orbits shows opacification of the left ethmoid sinus and bilateral sphenoid sinuses along with pre and post-septal inflammation of the left orbit. A lenticular fluid collection with rim enhancement is present along the medial wall of the left orbit. Axial CT with contrast of the orbits shows opacification of the bilateral ethmoid and maxillary sinuses along with pre and post-septal inflammation of the right orbit. No subperiosteal abscess was seen.