脳への塞栓源としての大動脈弓部粥腫の超音波診断

抄録

Several pathological studies have reported that emboli originating from atherosclerotic plaque in the aortic arch can be a cause of so-called cryptogenic stroke. Transesophageal echocardiography (TEE) has many advantages over other diagnostic tools including CT, MRA, and conventional aortography for evaluation of aortic atheroma. We previously proposed that plaque in the aortic arch with a maximal intima-medial thickness of > 3.0 mm and a markedly irregular surface or broad acoustic shadow on TEE was indicative of a pathology-proven complicated atheromatous lesion. Recent studies have often used the criterion of a maximal intima-medial thickness of > 4.0 mm as an indicator of an embologenic lesion, as proposed by the French Study of Aortic Plaques in Stroke Group. In addition, special plaque characteristics, including pedunculation, ulceration, and extension to the orifice of the branch arteries may contribute to stroke occurrence. Diagnostic guidelines for neurosonological examinations including TEE are being prepared by committee members of The Japan Academy of Neurosonology.