Comparison Between ED Ratio (End-diastolic Ratio) of the Common Carotid Arteries Using Duplex Method of Carotid Artery Ultrasonography and Brain Magnetic Resonance Angiography(Special Issue in Hornor of the Retirement of Professor Makoto Iwata at the Department of Neurology, Tokyo Women\u27s Medical University)

The end-diastolic (ED) ratio of both common carotid arteries (CCAs) is one of the parameters on carotid artery ultrasonography. ED ratio is calculated by side-to-side ratio of end-diastolic flow velocities (EDFVs) bilaterally. When the difference of EDFVs of both CCAs is over 30% (i.e., ED ratio of CCA is over 1.4), it suggests that the distal stenosis of the internal carotid artery (ICA) or middle cerebral artery (MCA) on the lower side of EDFV. We examined 185 patients (Acute Stroke group: 78 patients; Screening group: 107 patients) who had a 1.4<ED ratio and could be with brain magnetic resonance angiography (MRA). The Screening group contained patients with hypertension, hyperlipidemia, and/or diabetes mellitus, and some patients had an old stroke episode. Stenosis/occlusion of carotid axis by MRA presents in 72 patients (38.9%) from both groups and 43 patients (55.1%) in the Acute Stroke group. This is a higher percentage than in just the Screening group (29 patients, 27.1%). But all 3.0<ED ratio patients have arterial stenosis/occlusion. In 1.4