Superselective pseudocontinuous arterial spin labeling.

Area of Science:

• Medical Imaging
• Neuroimaging
• Vascular Biology

Background:

• Accurate imaging of cerebral arterial flow territories is crucial for diagnosing and managing cerebrovascular diseases.
• Existing techniques may lack the resolution or specificity to visualize small intracranial arteries effectively.

Purpose of the Study:

• To present a novel imaging technique for precisely mapping flow territories of individual extra- and intracranial arteries.
• To demonstrate the method's capability for superselective labeling of small cerebral arteries.

Main Methods:

• The technique is based on balanced pseudocontinuous arterial spin labeling (bASL) with added time-varying gradients.
• Gradient direction and radiofrequency pulse phases are manipulated to achieve efficient, targeted spin inversion.
• Simulations and experimental measurements investigated gradient timing effects on labeling efficiency and selectivity.

Main Results:

• The method demonstrated efficient inversion at the target vessel, with marginal inversion elsewhere.
• Labeling focus size can be adjusted by altering gradient moments.
• High signal-to-noise ratio images of small anterior cerebral artery branches were acquired in a volunteer study.

Conclusions:

• The new technique provides flexibility for imaging complex arterial geometries.
• It enables superselective labeling of small intracranial arteries, enhancing neurovascular imaging capabilities.