High-Resolution CT Feature of the Temporal Bone in Congenital Microtia

Objective: To assess HRCT findings in the temporal bone of patients with congenital microtia.Methods: HRCT imaging of the temporal bone and the abnormalities in the different structures of the temporal bone were reviewed in 54 cases(66 ears) with congenital microtia.Results: The bone part of the external auditory canal stenosis or atresia occured in 64 ears(97.0%),tympanic cavity stenosis or obliteration in 51 ears(77.3%),Ossicle dysplasia or absence in 58 ears(87.9%),oval window absence or partial absence in 11 ears(16.7%),round window absence in 3 ears(4.5 %),inner ear malformation in 6 ears(9.1 %),tympanic segment of facial nerve canal dislocation in 9 ears(13.6 %),mastoid segment of facial nerve canal anterior dislocation in 36 ears(54.5 %),highriding jugular bulb in 20 ears(30.3 %),sigmoid sinus anterior dislocation in 10 ears(15.2%),middle cranial fossa inferior dislocation in 23 ears(34.8 %).Conclusion: HRCT findings in the temporal bone of patients with congenital microtia are mostly the bone part of the external auditory canal stenosis or atresia,tympanic cavity stenosis or obliteration,Ossicle dysplasia or absence and mastoid segment of facial nerve canal anterior dislocation.The next often observed abnormalities are oval window absence or partial absence,tympanic segment of facial nerve canal dislocation,highriding jugular bulb,sigmoid sinus anterior dislocation and middle cranial fossa inferior dislocation.Inner ear malformation and round window absence are rare.