<unk>  <unk>  refers to<unk>  (widening) of an artery when blood<unk>  increases in that artery. The primary cause of<unk>  is release of nitric oxide by endothelial cells. To determine<unk> , brachial artery<unk>  following a transient period of forearm ischemia is measured using ultrasound. Because the value of<unk>  can be compromised when improperly applied, attempts have been made to standardize the methodology for measuring<unk> .
Flow-mediated dilation
Retrograde perfusion
Pressure reactivity index
Critical closing pressure
Myogenic tone
Vagal tone
Vascular resistance
Arterial input function