Intercaudate distance to inner table width ratio

Intercaudate distance to inner table width ratio (CC/IT) is used in assessing patients with neurodegenerative diseases that affect the caudate nuclei. It is best known for assessing individuals with suspected Huntington's disease but is in no way specific for the diagnosis, also seen in other less common diseases (e.g. Nasu Hakola disease).

On the same axial plane obtained on the ACPC (anterior commissure and posterior commissure) line, the ratio between the distance between the caudate heads (where they are closest) and the distance between inner table of the skull (measured along the same line as the intercaudate distance) is obtained. 

The normal CC/IT ratio range 0.09 to 0.12. As the caudate heads reduce in size, the CC distance will increase and as such the CC/IT ratio will increase.

An alternative measurement is the frontal horn width to intercaudate distance ratio (FH/CC).

Neurodegenerative diseases

Neurodegenerative diseases are legion and their classification just as protean. A useful approach is to divide them according to underlying pathological process, although even using this schema, there is much overlap and thus resulting confusion.

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Article information

rID: 28843
Synonyms or Alternate Spellings:
  • Intercaudate distance to inner table width ratio (CC/IT)
  • CC/IT

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Cases and figures

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    Figure 1: FH:CC ratio
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