Arterial Spin Labeling
Also written as: ASL — Arterial Spin Labeling
MRI technique that measures cerebral blood flow by magnetically labeling arterial blood water as an endogenous tracer.
Full Definition
Arterial Spin Labeling (ASL) is a non-invasive MRI perfusion technique that uses magnetically labeled arterial blood water as a natural tracer to quantify cerebral blood flow. Unlike contrast-enhanced perfusion methods, ASL requires no exogenous contrast agents, making it ideal for patients with renal dysfunction or contrast allergies. This technique provides quantitative cerebral blood flow measurements in ml/100g/min and is particularly valuable for assessing perfusion in stroke, vasospasm, and other neurovascular conditions. ASL is increasingly used in neurocritical care for monitoring cerebral perfusion changes over time.
Usage
Usage note: Specify whether pseudo-continuous or pulsed ASL technique was used.
In Context
- "Arterial spin labeling demonstrated reduced cerebral blood flow in the watershed territories consistent with hypoperfusion." — MRI report