use of transcranial doppler ultrasound to assess leptomeningeal collateral flow in patients with severe occlusive internal carotid and middle cerebral artery disorders: correlation with cerebral angiography

Background: the leptomeningeal collateral (lmc) is dynamic in ischemic stroke especially in internal carotid artery (ica) and middle cerebral artery (mca) disorders. transcranial doppler (tcd) is the only noninvasive and portable technique for the lmc; however, there is no standard for tcd in lmc assessment. objectives: to establish a reference for tcd to assess the lmc in severe occlusive ica and mca disorders. patients and methods: forty-four patients were divided into two groups according to the lmc flow in digital subtraction angiography (dsa). the velocities of the bilateral mca, anterior cerebral artery (aca), and posterior cerebral artery (pca) were analyzed. results: in the aca-lmc group, the ratio of the stenosis-side aca and mca were significantly increased for the systolic velocity (p = 0.003). the sensitivities and specificities were 68.4% and 80.0%, respectively, when the ratio was 2.27 (p = 0.006). in the pca-lmc group, the ratio of the stenosal side pca and the opposite side pca were significantly increased for the diastolic velocity (p = 0.031). the sensitivities and specificities were 77.8% and 75.0%, respectively, when the ratio was 1.38 (p = 0.026). conclusion: tcd is a reliable tool for lmc assessment in patients with severe occlusive ica and mca disorders.