Radiological signs indicating cholesteatoma in the attic included erosion or destruction of scutum or spur (the lateral wall of the attic), widening of the aditus ad antrum (loss of figure of "8" appearance) , antral wall erosions and widening , ossicular erosions and destruction , medial attic wall erosion which may lead to facial nerve canal involvement, which may cause paresis or paralysis , erosion of the lateral semicircular canal which may result into fistula formation (Figure 1), dehiscence of tegmen tympani
, dehiscence of sigmoid sinus plate, erosion of the external auditory canal (EAC), and automastoidectomy.
12] Other areas of erosion include the tegmen tympani
, the bony plate covering the sigmoid sinus, the squama of the temporal bone and rarely the vestibular labyrinth.
The exact anatomical location of the disease process, erosion of the bony boundaries of the middle ear, the status of the ossicular chain, tegmen tympani
, sigmoid sinus plate and lateral semicircular canals can be well visualized.
The scutum, ossicles, and tegmen tympani
are common sites for erosion.
Other cases have no connection to the CNS; instead, the connection may be provided by a small congenital defect in the tegmen tympani
or overlying temporal bone.
Preoperative CT establishes the type of surgical procedure as it determines the extent of the cholesteatoma, ocular chain involvement, facial canal integrity, and tegmen tympani
and dural plate involvement.
A small defect of 3mm size in the anterior aspect of tegmen tympani
with contrast leak in to left middle ear cavity and mastoid air cells with opacification of cotton swab kept in left external ear--Findings are suggestive of CSF otorrhoea.
or sinus plate erosions warrants the radiologist to find intracranial complications if any.
3-cm abscess at the left temporal lobe (figure 2) and a breach of the tegmen tympani
INTRODUCTION: In the well-pneumatized temporal bone, the temporal lobe of the brain is separated from the middle ear and the mastoid process by a thin layer of bone known as the tegmen tympani
Computed tomography showed a large, hyperdense dura-based mass along the left temporal bone invading the mastoid antrum, with destruction of the tegmen tympani
Otorhino-liquorrhoea results from disruption of dura in tegmen tympani