Rotated spiral RARE for high spatial and temporal resolution volumetric arterial spin labeling acquisition

• Published in: NeuroImage (Orlando, Fla.) Vol. 223; p. 117371
• Main Authors: Munsch, Fanny, Taso, Manuel, Zhao, Li, Lebel, R. Marc, Guidon, Arnaud, Detre, John A., Alsop, David C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2020; Elsevier Limited; Elsevier
• Subjects: Adult; Amygdala; Arterial spin labeling; Blood flow; Brain - anatomy & histology; Brain - diagnostic imaging; Brain connectivity; Brain mapping; Brain Mapping - methods; Compressed sensing; Female; Fourier transforms; Functional magnetic resonance imaging; Humans; Imaging, Three-Dimensional - methods; Magnetic Resonance Imaging - methods; Male; MRI; Neural networks; Neuroimaging; Noise; Noise reduction; Perfusion; Resting-state networks; Signal-To-Noise Ratio; Spin labeling; Spin Labels; Young Adult; Brain connectivity; MRI; Perfusion; Resting-state networks; Compressed sensing; Arterial spin labeling
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2020.117371

•3D spiral ASL can be accelerated without degradation of time average image quality.•Accelerated single-shot images enable measurement of flow fluctuations.•Resting-state networks can be studied in challenging regions for rs-BOLD MRI. Arterial Spin Labeling (ASL) MRI can provide quantitative images that are sensitive to both time averaged blood flow and its temporal fluctuations. 3D image acquisitions for ASL are desirable because they are more readily compatible with background suppression to reduce noise, can reduce signal loss and distortion, and provide uniform flow sensitivity across the brain. However, single-shot 3D acquisition for maximal temporal resolution typically involves degradation of image quality through blurring or noise amplification by parallel imaging. Here, we report a new approach to accelerate a common stack of spirals 3D image acquisition by pseudo golden-angle rotation and compressed sensing reconstruction without any degradation of time averaged blood flow images. 28 healthy volunteers were imaged at 3T with background-suppressed unbalanced pseudo-continuous ASL combined with a pseudo golden-angle Stack-of-Spirals 3D RARE readout. A fully-sampled perfusion-weighted volume was reconstructed by 3D non-uniform Fast Fourier Transform (nuFFT) followed by sum-of-squares combination of the 32 individual channels. Coil sensitivities were estimated followed by reconstruction of the 39 single-shot volumes using an L1-wavelet Compressed-Sensing reconstruction. Finally, brain connectivity analyses were performed in regions where BOLD signal suffers from low signal-to-noise ratio and susceptibility artifacts. Image quality, assessed with a non-reference 3D blurring metric, of full time averaged blood flow was comparable to a conventional interleaved acquisition. The temporal resolution provided by the acceleration enabled identification and quantification of resting-state networks even in inferior regions such as the amygdala and inferior frontal lobes, where susceptibility artifacts can degrade conventional resting-state fMRI acquisitions. This approach can provide measures of blood flow modulations and resting-state networks for free within any research or clinical protocol employing ASL for resting blood flow. [Display omitted]