It is important to evaluate for extension into mastoid air cells
, tegmen tympani integrity and facial nerve canal delineation, as these features may change the surgical management.
Minimal mucosal irregularity within mastoid air cells
may be associated with nonseptic lateral sinus thrombosis.
Opacification of the mastoid air cells is nonspecific and not indicative of acute mastoiditis but, rather, is often seen with acute otitis media (AOM), along with preservation of the ossicular chain, trabeculae, and cortical bone.
A diagnosis that could be consistent with MRI fluid signal in mastoid air cells was found in 9 patients (32%).
The MRI also detected evidence of bone destruction and tumor extension into the posterior fossa, jugular foramen, and mastoid air cells
If the mastoid air cells
are invaded, a modified radical mastoidectomy may be indicated, with the tympanic membrane and ossicles left intact.
Iatrogenic CSF leaks commonly occur through the cells of the petrous apex to the tympanic cavity or eustachian tube, through the perilabyrinthine cells to the mastoid antrum, through the mastoid air cells at the craniotomy site, or through an opened vestibule and oval window.
The opacification of the few opened mastoid air cells actually represented bone wax rather than CSE This obviated the need for a significantly more extensive procedure and allowed us to treat the patient with a transcanal procedure.
Erosion of the petrous bone and coalescence of mastoid air cells
The mass indented the left cerebellar hemisphere posteriorly and extended laterally to the mastoid air cells
(figure 1, B).
However, during canal-wall-down surgery that includes the creation of a cavum minor and interruption of normal mastoid drainage, Cheesman believed that it was necessary to "achieve total removal of all mastoid air cells
except those not disturbed by the cavity reconstruction.