Continuous ASL (CASL) perfusion MRI with an array coil and parallel imaging at 3T

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Neuroimaging
• Medical Physics

Background:

• Continuous arterial spin labeling (CASL) is a valuable MRI technique for assessing cerebral blood flow (CBF).
• Optimizing CASL performance requires advanced coil technology and imaging methods to overcome signal limitations and improve image quality.

Purpose of the Study:

• To evaluate the feasibility and effectiveness of employing an 8-channel array coil combined with parallel imaging for CASL perfusion MRI.
• To compare the performance of array coils with parallel imaging against standard volume coils in CASL.

Main Methods:

• CASL perfusion MRI scans were performed using a standard volume coil, an 8-channel array head coil, and the array coil with 2- and 3-fold parallel imaging acceleration.
• Key metrics assessed included signal-to-noise ratio (SNR), temporal stability, quantitative CBF, and perfusion image coverage.

Main Results:

• The array coil demonstrated a threefold increase in average SNR and enhanced temporal stability compared to the standard volume coil, even at 3-fold acceleration.
• Quantitative CBF images showed high reproducibility, unaffected by coil sensitivity inhomogeneities that impacted raw perfusion images.
• Parallel imaging facilitated acquisition of more slices and improved coverage in areas with magnetic field variations, while pairwise subtraction effectively mitigated EPI distortions.

Conclusions:

• Array coils and parallel imaging are highly beneficial for ASL perfusion MRI, offering improved SNR, temporal stability, and quantitative CBF accuracy.
• This combination holds significant potential for advancing neuroimaging applications requiring precise perfusion assessment.