A comparative study of imaging techniques and methods to measure cerebral vascular reactivity.

Abstract

Cerebrovascular Reactivity (CVR) reflects how well blood vessels are able to dilate or contract in response to a vasoactive stimulus. An impaired CVR may indicate cerebrovascular dysfunction. Various stimuli including breath-hold (BH), acetazolamide (ACZ) and breathing challenges are used to examine CVR. Changes in CVR have been observed using transcranial doppler ultrasonography (TCD), near-infrared spectroscopy (NIRS), and functional magnetic resonance imaging (fMRI). CVR stimulus response as well as the techniques employed to measure CVR are summarized in this paper.