Intramural blood pool (aorta)

Last revised by Joshua Yap on 12 Nov 2022

Intramural blood pools (IMBPs), also known as aortic branch artery pseudoaneurysms, are small foci of contrast enhancement within a recent aortic intramural hematoma seen on contrast-enhanced CT 2. They are more common in patients whose intramural hematoma thickness exceeds 10 mm.

Radiographic features


Intramural blood pools are located within the intramural hematoma and either do not visibly communicate with the true lumen, or do so only via a very small (<2 mm) ostium 1. They are most frequently located within the descending thoracic and abdominal aorta in hematomas at least 10 mm in thickness 1. Additionally, they are often associated with an adjacent intercostal artery or lumbar artery 1. Bronchial arteries are less commonly implicated 2.

Treatment and prognosis

Unlike ulcer-like projections, intramural blood pools do not adversely affect prognosis, often regress spontaneously, and require no dedicated treatment 1. CTA follow-up is important. Occasionally, endovascular coil embolization is offered to patients with enlarging symptomatic intramural blood pools 2.

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Cases and figures

  • Figure 1: illustration
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  • Case 1
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