Abstract
ABSTRACT
Purpose
To develop an efficient dynamic pseudo‐continuous arterial spin labeling (pCASL) MRI technique for whole‐brain microvascular flow pulsatility imaging.
Methods
The proposed technique combines pCASL with a segmented stack‐of‐stars golden‐angle radial acquisition. All collected k‐space segments were retrospectively binned into multiple cardiac phases according to the recorded pulse signal timings and reconstructed using compressed sensing. In vivo experiments were conducted in 25 participants on a 3 T MRI system. The segmented radial sampling scheme was evaluated and optimized, and results were cross‐validated with the reference using a single‐shot 3D GRASE acquisition. Test–retest experiments were conducted to evaluate the reproducibility of pulsatility index (PI) measurements. Further optimization, including reconstructions at different in‐plane spatial resolutions, shortening the total acquisition time through retrospective down‐sampling, and whole‐brain imaging with increased through‐plane resolution, was performed to investigate improvements in scan efficiency and whole‐brain PI delineation.
Results
Consistent PI measurements were obtained using the proposed acquisition scheme with different numbers (
M
) of radial spokes per segment, enabling improved scan efficiency with a higher
M
. Test–retest analysis demonstrated good reproducibility in PI measurements (ICC = 0.89,
p
Conclusion
The proposed technique enables reliable and efficient measurement of whole‐brain microvascular PI using segmented stack‐of‐stars radial acquisition.