Three-territory sign (brain)

Last revised by Rohit Sharma on 3 Mar 2024

Citation, DOI, disclosures and article data

Citation:

Sharma R, Bell D, Three-territory sign (brain). Reference article, Radiopaedia.org (Accessed on 24 Apr 2024) https://doi.org/10.53347/rID-149300

DOI:

https://doi.org/10.53347/rID-149300

Permalink:

https://radiopaedia.org/articles/149300

rID:

149300

Article created:

18 Jul 2022, Rohit Sharma ◉

Disclosures:

At the time the article was created Rohit Sharma had no recorded disclosures.

View Rohit Sharma's current disclosures

Last revised:

3 Mar 2024, Rohit Sharma ◉

Disclosures:

At the time the article was last revised Rohit Sharma had no financial relationships to ineligible companies to disclose.

View Rohit Sharma's current disclosures

Revisions:

5 times, by 2 contributors - see full revision history and disclosures

Systems:

Central Nervous System, Oncology

Sections:

Signs

Tags:

cases

Synonyms:

3-territory sign
Three territory sign

The three-territory sign is a radiological sign described in ischaemic stroke and is highly specific to hypercoagulability due to malignancy (Trousseau syndrome) being the aetiology. However, this sign is not pathognomonic, and may be seen with cardioembolic stroke (e.g. due to atrial fibrillation, endocarditis, cardiac tumours) or stroke due to other prothrombotic states (e.g. due to COVID-19) ^1-7.

The three-territory sign describes ischaemic strokes involving three vascular territories including involvement of the bilateral anterior and posterior circulations ^1-6. Often, the individual ischaemic strokes are small, rather than being large vessel occlusions ³. The sign is best appreciated with diffusion-weighted imaging on MRI ^1-6.

In one study, the three-territory sign was found to be highly specific (96.4%) but not sensitive (23.4%) for hypercoagulability due to malignancy (Trousseau syndrome) ¹. Notably, in the same study, the three-territory sign was six times more likely observed in patients with underlying malignancy when compared to patients with underlying atrial fibrillation who may have had multi-territory cardioembolic ischaemic stroke (i.e. embolic shower) ¹. In another study, the three-territory sign was found to be an independent marker of increased mortality in patients with acute ischaemic stroke in the setting of malignancy ⁶.