Resistive Index Analysis Using Doppler Ultrasonography in Patients with Acute Stroke

ABSTRACT

PURPOSE: To evaluate the usefulness of resistive index using carotid Doppler sonography for understanding hemodynamics in acute stroke patients. MATERIALS and METHODS: We retrospectively reviewed Doppler sonography in 97 acute stroke patients and 235 asymptomatic patients. We compared the resistive index between the ipsilateral and contralateral internal carotid arteries, and analyzed the relationship between the degree of stenosis and the resistive index of the internal carotid artery using linear regression analysis. We divided our patients into two groups according to the ASPECT score (7 and more and less than 7) determined from diffusion and T2 weighted images. Then we analyzed the difference of Doppler sonographic parameters between these two groups (independent t test). RESULTS: The resistive indices of both the ipsilateral internal carotid arteries of the acute stroke patients and the arteries of the asymptomatic patients showed a positive correlation with their respective degrees of stenosis (R2 = 0.127, p < 0.001; R2 = 0.046, p < 0.001, respectively). However, the resistive index of the contralateral internal carotid arteries was not correlated with their degree of stenosis (R2 = 0.016, p = 0.215). The resistive index of the ipsilateral internal carotid arteries in the acute stroke patients was significantly higher in the patients with ASPECT more than 7 than those with ASPECT score less than 7 (p = 0.002). CONCLUSION: Evaluation of the resistive index of the internal carotid arteries in acute stroke patients may be useful for understanding the cerebral hemodynamics.