Measurement of Anterior and Posterior Circulation Flow Contributions to Cerebral Blood Flow

Abstract

Ultrasound-derived volumetric flow analysis may be useful in answering questions of basic physiological interest in the cerebrovascular circulation. Using this technique, the authors have sought to describe quantitatively the complete concurrent flow relations among all four arteries supplying the brain. The aim of this study of normal subjects was to determine the relative flow contributions of the anterior (internal carotid arteries) and posterior (vertebral arteries) cerebral circulation. Comparisons between the observed and theoretically expected anterior and posterior flow distribution would provide an opportunity to assess traditional rheological conceptions in vivo. Pulsed color Doppler ultrasonography was used to measure mean flow rates in the internal carotid and vertebral arteries in 21 normal adults. The anterior circulation (internal carotid arteries bilaterally) carried 82% of the brain's blood supply and comprised 67% of the total vascular cross-sectional area. These values demonstrate precise concordance between observations in vivo and the theoretically derived (Hagen-Poiseuille) expected flow distribution. These cerebrovascular findings support the traditional conception of macroscopic blood flow. Further studies using ultrasound-derived volumetric analysis of the brain's arterial flow relations may illuminate the vascular pathophysiology underlying aging, cerebral ischemia, and dementias.

A theoretical model of selective cooling using intracarotid cold saline infusion in the human brain

“…According to baseline white and gray matter perfusion values and Eq. 12, ICA blood flow rate before cold saline infusion in a healthy brain was ϳ250 ml/min, corresponding to published values (4,45,50,51). Figure 6A shows that the initial blood flow rate was reset to Ͼ250 ml/min after induction of the saline infusion.…”

“…The anterior circulation (ICA) carries 75% of the brain's blood supply and comprises 75% of the total vascular volume, while the posterior circulation (vertebrals) supplies the remaining 25%. These values accurately reflect the relative contributions of the anterior and posterior circulation, derived through color duplex sonography and phase-contrast MRI, that range from 67% to 82% for the ICAs (4,45,50,51). Given that the ipsilateral ICA perfused threequarters of the corresponding brain hemisphere, the brain volume receiving the intra-arterial cold perfusate was 482 ml, and the corresponding brain mass was 496 g. The model assumed no mixing of blood between the posterior and anterior circulations and a sharp demarcation of the two vascular sections without arterial boundary zones (Fig.…”

Vertigo: Analysis by Magnetic Resonance Imaging and Angiography

“…Flow data derived from ultrasound were reported by Boyajian et al 14 The data from cross-sectional measurements indicate that the carotid arteries make up 67% of the total vascular area. The flow volumes through the individual cervical vessels were derived from ultrasonic studies; the data are presented in Table 1.…”

A Novel Technique for Simulating Transcranial Doppler Examinations In Vitro

“…The system was set to deliver 82% through the anterior circulation, and 18% through the posterior circulation. This simulates the typical in vivo distributions [10].…”