Head and Neck ImagingCochlea, pathology
According to Jackler,
inner ear
malformations can be divided into a group with and a group without cochlear malformations. Those with cochlear malformations can be categorized as follows:
-
congenital labyrinthine aplasia (
Michel aplasia
);
- common cavity (cochlea and vestibule);
- cochlear aplasia (with normal vestibule and semicircular canals) (
Fig. 1);
- cochlear hypoplasia; and
- incomplete partition ('true'
Mondini's malformation
, absence of interscalar septum)
Additionally, anomalies of the modiolus (see
cochlea
) have been recognized (see
modiolus anomalies
).
Several types of
inflammation can affect the cochlea: viral or bacterial infection and autoimmune disease, see
labyrinthitis
.
Otodystrophies
The otodystrophies that may affect the cochlea are:
otosclerosis
,
Paget's disease
,
fibrous dysplasia, head and neck
,
osteopetrosis
and
osteogenesis imperfecta
.
Cochlear tumours may arise from within the membranous labyrinth (vestibular or cochlear schwannoma). Intracanalicular acoustic schwannoma may extend into the cochlea along the cochlear nerve (see also
hook shape sign, in acoustic schwannoma
). Tumours originating in the region of the cochlea may invade its bony
capsule (e.g.
glomus tumour
).
The cochlea may be involved in a
transverse fracture, temporal bone
. Hearing loss may be due to cochlear concussion, without a
fracture visible on
CT. Post-traumatic serous labyrinthitis or cochlear
haematoma (
Fig. 2) may be revealed on
MRI.
RH
To view high resolution images,
please register first.
Click
here
to register.
Already registered? Enter your e-mail in the window below.Re-registerFig. 01a
Maximum intensity projection of thin-section axial T2-weighted fast spin echo images of temporal bones. Normal appearance of the left cochlea, vestibulum and semicircular canals. On the right side, the cochlea and vestibule appear as a common cavity (arrowhead); the semicircular canals are present but somewhat dysplastic (arrows) (courtesy by Patrick Seynaeve, MD, Kortrijk, Belgium).
 | |  | |  |
Cochlea, pathology, Fig. 01a | | Cochlea, pathology, Fig. 02a (a) | | Cochlea, pathology, Fig. 02b (b) |