Cochlear incomplete partition type II
Cochlear incomplete partition type II (IP-II) is a type of cochlear anomaly associated with sensorineural hearing loss.
It should not be confused with Mondini anomaly, which is a historic term for a combination of IP-II and large vestibular aqueduct.
Radiographic features
CT
On CT, the cochlea is seen as having only 1 1/2 turns with coalescence of the apical and middle turn, forming a cystic apex .
Other findings include :
- absent interscalar septum
- absent osseous spiral lamina
- absent or deficient modiolus
- only normal at level of basal turn
- normal basal turn of the cochlea
- vestibular aqueduct enlargement very common
- can be normal, but rare
- normal vestibule
MR
Care should be taken when interpreting MR in isolation for cochlear incomplete partition; it should always be correlated to petrous temporal bone CT-scan .
- T2: on thin sections, absence of interscalar septum and spiral lamina at the level of apical and middle turns may be seen
See also
