Evaluation of Absolute Cerebral Blood Flow by Laser-Doppler Scanning – Comparison with Hydrogen Clearance

• Published in: Journal of vascular research Vol. 36; no. 2; pp. 100 - 105
• Main Authors: Uranishi, Ryunosuke, Nakase, Hiroyuki, Sakaki, Toshisuke, Kempski, Oliver S.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Basel, Switzerland Karger 01.03.1999; S. Karger AG
• Subjects: Animals; Biological and medical sciences; Brain Ischemia - physiopathology; Cerebral circulation. Blood-brain barrier. Choroid plexus. Cerebrospinal fluid. Circumventricular organ. Meninges; Cerebrovascular Circulation - physiology; Evaluation Studies as Topic; Fundamental and applied biological sciences. Psychology; Hydrogen - blood; Hydrogen - pharmacokinetics; Hypotension - physiopathology; Laser-Doppler Flowmetry; Male; Rats; Rats, Wistar; Reference Values; Research Paper; Vertebrates: nervous system and sense organs; Laser-Doppler flowmetry; Global ischemia; Rat; Cerebral blood flow; Laser-Doppler scanning; Regional blood flow; Evaluation; Rodentia; Central nervous system; Vertebrata; Laser dopplerometry; Mammalia; Ischemia; Hemodynamics; Measurement method; Flowmetry; Brain (vertebrata)
• ISSN: 1018-1172; 1423-0135
• DOI: 10.1159/000025631

A major limitation of laser-Doppler (LD) flowmetry, which enables noninvasive and continuous recording of tissue perfusion, is its inability to evaluate the absolute cerebral blood flow (CBF). Using a computer-controlled micromanipulator, the LD scanning technique provides information on the brain microcirculation in many different locations, information which is not available from a single stationary probe. The purpose of the current study was to examine whether LD scanning estimates can be calibrated for the absolute CBF by comparing LD scanning with the hydrogen clearance (HC) method. In Wistar rats (n = 31) including old rats (122–123 weeks old, n = 8), the CBF was altered using the global ischemia model by bilateral carotid artery occlusion coupled with hypobaric hypotension. The CBF was determined simultaneously by the LD scanning technique and HC at each mean arterial blood pressure step, and the correlation of CBF between the two techniques was analyzed. CBF measured by LD scanning was expressed as LD units. Absolute CBF values obtained by methods were correlated (r = 0.87), and the formula to calibrate absolute CBF values from LD units was y = 1.8x – 0.6. On the other hand, in old rats the formula to calibrate the absolute values was different (y = 1.3x + 8.3, r = 0.85). The results suggest that CBF data obtained by LD scanning could be calibrated into absolute blood flow values in particular circumstances, and that LD scanning could compensate in part for the weakness of LD flowmetry.