arterial spin labeling
Non-invasive MRI perfusion technique that uses magnetically labeled arterial blood water as an endogenous tracer to measure cerebral blood flow.
Full Definition
Arterial spin labeling (ASL) is an advanced MRI technique that provides quantitative measurements of cerebral blood flow without requiring exogenous contrast agents. The method works by magnetically inverting or saturating arterial blood water protons upstream from the imaging region, creating an endogenous tracer. After a delay period, images are acquired and compared with control images to generate perfusion maps. ASL is particularly valuable in pediatric populations, patients with renal impairment, and research studies requiring repeated perfusion measurements. The technique provides absolute quantification of CBF in units of mL/100g/min.
Usage
Usage note: Spell out on first use, then ASL is acceptable; avoid confusion with American Sign Language.
In Context
- "Arterial spin labeling demonstrated hypoperfusion in the watershed territories without contrast administration." — Pediatric imaging report
- "The research protocol utilized arterial spin labeling to avoid cumulative gadolinium exposure in longitudinal studies." — Research methodology