A case in which superb microvascular imaging was useful for the diagnosis of brachiocephalic artery mobile plaque

Abstract

Brachiocephalic artery plaque may be an embolic source as a cause of cerebral infarction. We report a case in which a movable brachiocephalic artery plaque was diagnosed using ultrasound and in which a movable lesion was clearly visualized using superb microvascular imaging (SMI). A 77-year-old woman presented to our hospital with dysarthria and ataxia of the right upper extremity, scoring 2 on the National Institute of Health Stroke Scale. Head magnetic resonance imaging showed multiple cerebral emboli in the right cerebellar hemisphere, pons, and left temporal lobe. Transesophageal echocardiography performed to search for the source of the embolus revealed a mobile plaque in the brachiocephalic artery, which was scanned from the body surface with a sector-type probe. The depth of the plaque was so deep that it was necessary to differentiate it from artifacts, so SMI was used. The patient was diagnosed as having an embolic source at the same site and was treated medically with antiplatelet agents. The patient has since been followed up via ultrasound to monitor the morphology of the plaque. SMI can be used to analyze the characteristics of tissue motion and separate slow blood flow from tissue motion. The mechanisms by which mobile plaques become apparent with SMI include clutter motion with hypermobility due to motion artifacts and strong reflection intensity. In the present case, SMI was useful in the evaluation of mobile brachiocephalic artery plaques using a sector-type probe.