The dynamics of cerebrovascular reactivity shown with transfer function analysis.

摘要: Cerebrovascular reactivity (CVR) is often defined as the increase in cerebral blood flow (CBF) produced by an carbon dioxide (CO2) and may be used clinically to assess health of cerebrovasculature. When CBF estimated using oxygen level dependent (BOLD) magnetic resonance imaging, CVR values for each voxel can displayed a color scale mapped onto corresponding anatomical scan. While these maps therefore show distribution cerebrovascular reactivity, they only provide estimate magnitude response, do not indicate time course response; whether rapid or slow. Here we describe transfer function analysis (TFA) BOLD response CO2 that provides (gain) but also phase coherence. The interpreted indicating speed so distinguish areas where slowed. coherence measures fidelity with which follows stimulus. examples gain, obtained from TFA previously recorded test data patients healthy individuals demonstrate enhance assessment pathophysiology providing insight into dynamics control distribution.