[Carotid dislocation. The pictures with computed tomography and magnetic resonance]

Prevertebral retropharyngeal soft tissue widening can be recognized in acute trauma patients in the presence of acute bleeding from cervical vertebral fracture. Abscesses, tumors and neoplastic effusions from nearby cervical spaces can also widen precervical soft tissues and a new cause has been recently suggested, that is the so-called carotid transposition.

We examined eight patients (six women and two men) aged 65 to 75 years. Carotid transposition was found in four patients during examination for acute cervical trauma, while four cases were detected at CT studies performed for other indications, mostly lymphoma staging. CT was always performed with the i.v. injection of a contrast agent and volume scans were used in four cases. MR angiography (MRA) was also used in two patients to study an internal carotid artery stenosis previously detected at color Doppler.

Lateral radiographs of the cervical spine of our acute trauma patients showed widened soft tissues in three cases, but no calcific arterial plaques were found. The common carotid arteries were displaced in five patients and the internal carotid arteries in three. Carotid transposition was bilateral in six patients while only the right common and the left internal carotids were involved in two patients. No traumatic hemorrhagic effusion was found on CT images.

Carotid transposition is a mostly asymptomatic abnormality, but it must be considered in acute cervical trauma patients where the precervical soft tissues are widened because hemorrhagic effusion could be misdiagnosed. Thus, this unusual location of the carotid arteries is important because these vessels may be injured during emergency or surgical procedures.