Hemodynamic Evaluation of the Extracranial Internal Carotid Artery and Middle Cerebral Artery in Patients with Cerebral Infarction Using Ultrasound

Abstract

We hypothesized that hemodynamic parameters of the extracranial internal carotid artery (ICA) can reflect hemodynamic change in the middle cerebral artery (MCA) in patients with cerebral infarction (CI). In order to test this hypothesis, we evaluated the hemodynamic relationship between the ICA and MCA. We used TC-CFI and carotid ultrasonography to examine patients with CI within 14 days after onset. In 44 patients with bilateral temporal echo windows without severe stenosis or occlusion of the ICA, the hemodynamic correlation between the ICA and the MCA was evaluated for five parameters (peak systolic velocity, end-diastolic velocity, time-averaged maximum velocity, resistance index, and pulsatility index: PI). In 28 patients who had a CI in the MCA territory, PI showed a reasonable correlation between the two arteries (r=0.71 on the normal side, r=0.68 on the lesion side). Patients in whom the PI value demonstrated a larger value on one side were divisible into the following four groups: A; PI in both the ICA and MCA> 1.0, B; PI-MCA>1.0 and PI-ICA<1.0, C; PI-MCA< and PI-ICA>1.0, D; PI in both arteries<1.0. Almost all of the patients in group A (53.8%) had a history of severe vascular disease (SVD). Measurement of PI in the extracranial ICA can be useful for predicting the hemodynamic condition of the MCA in patients with CI, including those with SVD.