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
CT
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. Aortic branches less commonly implicated include the bronchial arteries 2.
Treatment and prognosis
Unlike ulcer-like projections, intramural blood pools to 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.