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 his an 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 1.

Other findings include 1,2:

  • 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 3.

  • T2: on thin sections, absence of interscalar septum and spiral lamina at the level of apical and middle turns may be seen 1

See also

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Article information

rID: 55582
Synonyms or Alternate Spellings:
  • IP-II

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