RT Journal Article SR Electronic T1 Cranial CT of autosomal recessive osteopetrosis. JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 543 OP 550 VO 10 IS 3 A1 Bartynski, W S A1 Barnes, P D A1 Wallman, J K YR 1989 UL http://www.ajnr.org/content/10/3/543.abstract AB Eight infants with radiographic and bone biopsy evidence of autosomal recessive osteopetrosis were evaluated by cranial CT. The clinical presentations and CT characteristics support the theory that this disorder exhibits severe and mild variants. At an early stage the severe variant demonstrates small optic canals, small orbits with proptosis, and a small nasoethmoid complex without significant bone thickening. The paranasal sinuses show bud formation but no pneumatization. The temporal bone retains a fetal appearance with trumpet-shaped internal auditory canals, prominent subarcuate fossae, and no mastoid pneumatization. The ventricles and subarachnoid spaces are enlarged. Bone thickness increases with age, leading to further orbital encroachment. Similar but less severe features are present in the mild variant. Underdevelopment of the orbits, nasoethmoid complex, and temporal bone suggests that delayed maturation is the primary morphologic abnormality of the skull base in osteopetrosis, and that bone thickening is a secondary manifestation caused by reduced bone turnover.