An introduction to ASL labeling techniques.

Area of Science:

• Medical Imaging
• Physiology
• Biophysics

Background:

• Arterial spin labeling (ASL) enables quantitative tissue perfusion assessment without contrast agents.
• The technique relies on magnetically labeling arterial blood water and observing its delivery to tissues.
• ASL provides absolute perfusion quantification, crucial for various clinical and research applications.

Purpose of the Study:

• To review and compare different classes of arterial spin labeling (ASL) methods.
• To discuss the quantification of perfusion using ASL data.
• To explore novel applications of ASL for extracting additional physiological information.

Main Methods:

• Comparison of continuous, pulsed, and velocity-selective ASL labeling strategies.
• Discussion of perfusion quantification algorithms for ASL data.
• Description of advanced ASL techniques for vascular territory and venous oxygenation mapping.

Main Results:

• ASL methods provide non-invasive, quantitative perfusion measurements in absolute units.
• Continuous, pulsed, and velocity-selective labeling techniques offer distinct advantages and applications.
• ASL can be extended to map vascular territories and assess venous oxygenation.

Conclusions:

• Arterial spin labeling is a versatile tool for quantitative perfusion imaging.
• Understanding different ASL methods is key to optimizing their application.
• Emerging ASL techniques promise expanded capabilities in physiological assessment.