Superficial temporal artery pseudoaneurysm: what is the role of ultrasound?

PURPOSE: The superficial temporal artery (STA) is one of the terminal branches of the external carotid artery; STA pseudoaneurysms are uncommon vascular lesion, generally subsequent to blunt or penetrating trauma that could represent a trick for radiologist, especially when the only anamnestic information is "palpable superficial swelling". In this article, we describe our ultrasonographic experience about STA pseudoaneurysm reporting several cases with different etiopatogenesis.

METHODS: Between January 2004 and March 2015 six patients (4F and 2M; aged 15-55 years, mean 36 year) presented at our department with superficial palpable swelling in temporal region (four with trauma history, two with iatrogenic cause) underwent to ultrasonographic study to assess the presence of STA pseudoaneurysm. Ultrasonographic findings suggestive of pseudoaneurysm was a well-defined, pulsatile, anechoic mass in B-mode, a swirling or disorganized pattern of blood flow in the lesion with demonstration of direct communication between arterial lumen and pseudoaneurysm at colour-Doppler and a typical to-and-fro waveform on pseudoaneurysm neck at pulsed-Doppler.

RESULTS: B-mode proves the presence of anechoic mass in five on six patients. Colour-Doppler demonstrates the presence of flow inside the lesion in five patients and a direct communication in all patients. To-and-fro typical waveform has been demonstrated in five patients. Ultrasound made diagnosis in all patients with a sensibility and specificity of 100 %.

CONCLUSION: US is the imaging modality of choice, since it can provide detailed information about vascular anatomy without incurring the risks of invasive methods like angiography or radiation.