The subarcuate fossa and channel. A radioanatomic investigation.

The subarcuate channel conveys the blood supply to the otic capsule of the semicircular canals, to part of the vestibule and to other neighbouring structures. It is often observed in conventional radiographs of the temporal bone and is reproduced to advantage by conventional multidirectional and computed tomography. The purpose of this report is to draw the attention of otoradiologists to this anatomic structure and to report on some results concerning the radioanatomy of the channel. Plastic casts of 100 radiographed and subsequently macerated temporal bones were evaluated. Fourteen temporal bone specimens were submitted to automatic serial cryomicrotomy. The radioanatomic variations of the channel were demonstrated. The radiographic reproducibility of the channel, length and width, were found to be dependent on the degree of perilabyrinthine and mastoid pneumatization of the temporal bone.