Frontal horn width to intercaudate distance ratio

Frontal horn
width to intercaudate distance ratio • Huntington disease - Ganzer Fall bei Radiopaedia
El-Feky M, Huntington disease. Case study, Radiopaedia.org (Accessed on 19 Apr 2023) https://doi.org/10.53347/rID-56374 • CC by-nc-sa 3.0 (modified)
Frontal horn
width to intercaudate distance ratio • Huntington disease - Ganzer Fall bei Radiopaedia
Haouimi A, Huntington disease. Case study, Radiopaedia.org (Accessed on 19 Apr 2023) https://doi.org/10.53347/rID-98523 • CC by-nc-sa 3.0 (modified)
Radiopaedia • CC-by-nc-sa 3.0 • de

Frontal horn width to intercaudate distance ratio (FH/CC) is used in assessing patients with suspected Huntington disease. An alternative measurement is intercaudate distance to inner table width ratio (CC/IT).

Measurement

On the same axial plane obtained on the ACPC (anterior commissure and posterior commissure) line, the ratio between the lateral margins of the frontal horns and the distance between the caudate heads (where they are closest).

Interpretation

The normal mean FH/CC ratio range is 2.2 to 2.6. As the caudate heads reduce in volume the CC distance will approach the FH distance, and the ratio will approach 1.