Ultrasound diagnosis of cervical artery dissection.

Ultrasound allows the reliable exclusion of spontaneous dissection of the cervical internal carotid artery (sICAD) in patients with carotid territory ischemia. The possibility of falsely positive ultrasound findings indicates that cervical magnetic resonance imaging (MRI) and angiography must confirm ultrasonic suspicion of sICAD. The sensitivity of ultrasound for assessing sICAD which causes no carotid territory ischemia, but headache, neck pain, Horner syndrome, or palsy of the cranial nerves on the side of dissection is about 70%, and for identifying spontaneous dissection of the vertebral artery (sVAD) the sensitivity is 75-86%. The negative predictive value and specificity for ultrasound diagnosis of the latter two types of cervical artery dissection is unknown. Consequently, all patients with clinical suspicion of sICAD causing no ischemic event or sVAD should undergo cervical MRI and angiography. Ultrasound is useful for noninvasive monitoring of vessel recanalization and for determining the duration of antithrombotic therapy.