What can we learn from arterial spin labeling MRI about pain?

Arterial spin labeling (ASL) has recently become a promising new tool in the investigation of various pathological states including chronic pain. In contrast to the most widely used BOLD fMRI, it provides a direct measure of tissue perfusion and is more sensitive for experimental paradigms with long periods – a feature that is critical particularly in the investigation of persistent pain states. Recently published ASL data on experimental pain confirm activations in previously identified pain-sensitive brain regions but also allowed for the direct quantification of the increase and decrease in blood flow. ASL is…