Ultrasound diagnosis of an internal carotid artery pseudoaneurysm in a young child.

Pseudoaneurysm of the carotid artery is a rare complication of deep neck space infection. It carries a high mortality rate even when treated appropriately. We report a case of a pseudoaneurysm of the internal carotid artery in a 2-year-old child who had a neck infection without an associated abscess. The diagnosis was not obvious on MRI but was confirmed by ultrasonography. This was successfully managed by angiographic embolization, followed by antibiotic and anticoagulant treatment. The combination of MRI and ultrasonography, without the use of invasive or radiation techniques, was sufficient for the diagnosis of pseudoaneurysm of the internal carotid artery.