Assessment of cerebral blood flow by means of blood-flow-volume measurement in the internal carotid artery: comparative study with a 133xenon clearance technique

Stroke. 2003 Aug;34(8):1876-80. doi: 10.1161/01.STR.0000080942.32331.39. Epub 2003 Jul 3.

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< or =8) and 4 patients with subarachnoid hemorrhage due to aneurysm rupture. In all patients and subjects, cerebral blood flow (CBF) values obtained with the 133xenon-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<0.0001). Global CBF values showed a higher correlation with the total BFV value obtained from both ICAs (r=0.84, P<0.0001). With 37 mL x min(-1) x 100 g(-1) as a cutoff value for the ischemic range, a BFV value of 220 mL/min would yield a positive predictive value of 91.7% and a negative predictive value of 82.6% (sensitivity 73.3%, specificity 95%). Conversely, BFV sensitivity and specificity were 60% and 96%, respectively, for the hyperemic range defined by a CBF value >55 mL x min(-1) x 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 133xenon-clearance technique. These results support the implementation of this technique for bedside assessment of cerebral hemodynamics in critically ill neurosurgical patients.

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Blood Flow Velocity
  • Blood Volume Determination / instrumentation
  • Brain Injuries / physiopathology*
  • Carotid Artery, Internal / diagnostic imaging*
  • Cerebrovascular Circulation*
  • Female
  • Humans
  • Intensive Care Units
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Reference Values
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Subarachnoid Hemorrhage / physiopathology*
  • Ultrasonography, Doppler / instrumentation*
  • Ultrasonography, Doppler / methods
  • Xenon Radioisotopes / pharmacokinetics

Substances

  • Xenon Radioisotopes