Assessment of Cerebral Blood Flow by Means of Blood-Flow-Volume Measurement in the Internal Carotid Artery

Abstract

Background and Purpose— We sought to evaluate a new, angle-independent ultrasonic device for assessment of blood flow volume (BFV) in the internal carotid artery (ICA). Methods— Nineteen patients and 4 healthy volunteers were enrolled in a comparative study conducted in the Care Unit of the Division of Neurosurgery at UCLA Medical Center. All patients had been admitted because of severe brain injury: 15 patients with severe head trauma (Glasgow Coma Scale score≤8) and 4 patients with subarachnoid hemorrhage due to aneurysm rupture. In all patients and subjects, cerebral blood flow (CBF) values obtained with the ¹³³ xenon-clearance technique were compared with BFV measurements in the ipsilateral ICA. Results— Hemispheric CBF values showed a close and linear correlation with BFV measurements ( r =0.76, P r =0.84, P 55 mL · min ⁻¹ · 100 g ⁻¹ (positive predictive value of 85.7% and negative prediction value of 85.7%). Conclusions— BFV measurements with this new technology proved to accurately correlate with CBF values evaluated by the ¹³³ xenon-clearance technique. These results support the implementation of this technique for bedside assessment of cerebral hemodynamics in critically ill neurosurgical patients.