Stroke requires rapid determination of the cause to provide timely and appropriate initial management. Various ultrasonographic techniques have been evaluated as ways to determine the cause of stroke; among them, carotid artery ultrasonography is particularly useful since it provides considerable information within a short time period when used to evaluate a specific site. In the emergency room, carotid artery ultrasonography can be used to diagnose internal carotid artery stenosis, predict an occluded vessel, and infer the cause of ischemic stroke. Additionally, carotid artery ultrasonography can diagnose different conditions including subclavian artery steal syndrome, bow hunter’s stroke, Takayasu’s arteritis, moyamoya disease, and dural arteriovenous fistula. Furthermore, patients with ischemic stroke with a pulse deficit or hypotension must be differentiated from acute type A aortic dissection, which requires emergency surgery; carotid artery ultrasonography can immediately differentiate between the two conditions by identifying the intimal flap of the common carotid artery. The following article provides an overview of carotid artery ultrasonography performed as point-of-care ultrasound in the emergency room in patients with suspected stroke.
