CT of the temporal bones demonstrates a comminuted oblique longitudinal fracture of the left temporal bone. An anterior fracture line passes inferiorly along the parietal bone, squamous part of temporal bone at lateral margin and lateral floor of the left middle cranial fossa.
The lateral wall demonstrates a depressed fragment with a fracture line involving posterior aspect of mandibular fossa, in the region of the petrotympanic fissure, posteriorly into the tympanic part of the temporal bone and anterior aspect of bony external auditory meatus.
Anteromedially the fracture line continues along the middle cranial fossa to foramen ovale and to margin of left foramen lacerum.
A posterior fracture line passes obliquely inferiorly from a diastased left lambdoid suture and across left petrous temporal bone, through the tegmen tympani.
There is subluxation between the incus and malleus. There is also opacification of left mastoid air cells.