The subarcuate canaliculus and its artery--a radioanatomical study.

The anatomy of the subarcuate canaliculus (SAC), subarcuate fossa (SAF) and subarcuate artery (SAA) was studied in 12 cadavers and 35 dry temporal bones. Each cadaver was scanned with high resolution CT (HRCT) prior to microdissection. The SAC was always found to be a single canal located between the two arcs of the anterior semicircular canal in both microdissections and HRCT scans and the internal acoustic meatus was observed to be located just inferior to the SAC. The SAC was on average of 9.2 mm in length and 1 mm in width. The SAF was situated at a distance of 4.2 mm from the internal acoustic meatus, 3.5 mm from the groove for the superior petrosal sinus, 6.7 mm from the opening of the vestibular canaliculus and 11.5 mm from the most superior part of the jugular foramen. The SAA was found to originate from the anterior inferior cerebellar artery in 9 cadavers and from the internal auditory artery in 3 cadavers. The SAA always emerged from the main artery outside the internal acoustic meatus. It ran through the SAC as a single artery. This study investigated CT correlated anatomical aspects of the subarcuate canaliculus and its artery which is claimed to be responsible for the blood supply of the mastoid antrum, facial canal and bony labyrinth.