Tau sign
Citation, DOI, disclosures and article data
Citation:
Jha P, Murphy A, Elfeky M, et al. Tau sign. Reference article, Radiopaedia.org (Accessed on 23 Mar 2025) https://doi.org/10.53347/rID-17589
Permalink:
rID:
17589
Article created:
27 Apr 2012,
Praveen Jha
Disclosures:
At the time the article was created Praveen Jha had no recorded disclosures.
View Praveen Jha's current disclosures
Last revised:
Disclosures:
At the time the article was last revised Daniel J Bell had no financial relationships to ineligible companies to disclose.
View Daniel J Bell's current disclosures
Revisions:
13 times, by
10 contributors -
see full revision history and disclosures
Systems:
Sections:
Synonyms:
- Tau sign (persistent primitive trigeminal artery)
- Tau signs
The tau sign represents the appearance of a persistent primitive trigeminal artery on the sagittal plane of an angiogram or on sagittal MRI. It resembles the Greek letter τ, pronounced "tau", and is equivalent to the modern-day "T" in the Latin alphabet.
The persistent trigeminal artery arises from the junction between the petrous and cavernous ICA and runs posterolaterally along the trigeminal nerve through, or adjacent to, the cavernous sinus.
The vertical and anterior horizontal limbs of "tau" are formed by the internal carotid artery (ICA) and the posterior horizontal limb is formed by the proximal portion of the persistent trigeminal artery.
References
- 1. Chavhan GB, Shroff MM. Twenty classic signs in neuroradiology: A pictorial essay. Indian J Radiol Imaging. 19 (2): 135-45. doi:10.4103/0971-3026.50835 - Free text at pubmed - Pubmed citation
- 2. Goyal M. The tau sign. (2001) Radiology. 220 (3): 618-9. doi:10.1148/radiol.2202991498 - Pubmed
Incoming Links
Articles:
Cases:
- Pontine haemorrhage with hypertensive microangiopathy and persistent trigeminal artery
- Persistent primitive trigeminal artery
- Persistent primitive trigeminal artery- Saltzman type I
- Persistent primitive trigeminal artery- Saltzman type II
- Primitive trigeminal artery with fetal PCOM
- Persistent trigeminal artery
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