Shielded dual-loop resonator for arterial spin labeling at the neck

Area of Science:

• Magnetic Resonance Imaging
• Biomedical Engineering
• Radiology

Background:

• Continuous arterial spin labeling (CASL) is crucial for non-invasive perfusion quantification.
• Developing specialized coils is essential for optimizing CASL performance in specific anatomical regions like the human neck.

Purpose of the Study:

• To design and characterize a novel dual-loop coil for CASL at the human neck.
• To evaluate coil performance using computational simulations and experimental magnetic resonance (MR) studies.

Main Methods:

• A dual-loop resonator coil was constructed using shielded coaxial cables for minimal tissue interaction.
• Three excitation modes (Maxwell, quadrature, Helmholtz) were investigated.
• Simulations and MR experiments were conducted at 3 Tesla (3T) in healthy volunteers.

Main Results:

• Simulations predicted high inversion efficiency in carotid and vertebral arteries.
• The coil design ensured a safe local specific absorption rate (SAR) well below limits.
• Quantitative gray matter perfusion maps demonstrated low intersubject variability.

Conclusions:

• The developed dual-loop coil enables robust CASL with low SAR.
• The coil exhibits minimal sensitivity to varying loading conditions, enhancing reliability.