arterial spin labeling
Also written as: ASL — Arterial Spin Labeling
Non-contrast MRI perfusion technique using magnetically labeled blood as an endogenous tracer to measure cerebral blood flow.
Full Definition
Arterial spin labeling (ASL) is a non-invasive MRI perfusion technique that magnetically labels arterial blood water as it flows into the brain, eliminating the need for exogenous contrast agents. This technique provides quantitative measurements of cerebral blood flow and is particularly valuable in patients with renal insufficiency or contrast allergies. ASL is increasingly used in stroke evaluation, tumor assessment, and research applications where repeated perfusion measurements are needed without the cumulative risks associated with gadolinium-based contrast agents.
Usage
Usage note: Emphasize non-contrast nature when relevant to patient care decisions.
In Context
- "ASL perfusion demonstrated hypoperfusion in the right temporal lobe without contrast administration." — MRI report for renal failure patient
- "Arterial spin labeling revealed asymmetrically decreased cerebral blood flow in the affected hemisphere." — Research protocol imaging