Advancing 7T perfusion imaging by pulsed arterial spin labeling: Using a parallel transmit coil for enhanced labeling robustness and temporal SNR

PLoS ONE, vol. 19, pp. e0309204

Abstract

Non-invasive perfusion imaging by Arterial spin labeling (ASL) can be advantageous at Ultra-high field (UHF) MRI, since the image SNR and the T1 relaxation time both increase with the static field. However, ASL implementation, especially at 7T, is not trivial. Especially for ASL, UHF MRI comes with many challenges, mainly due to B1+ inhomogeneities. This study aimed to investigate the effects of different transmit coil configurations on perfusion-weighted imaging at 7T using a flow-sensitive alternating inversion recovery (FAIR) technique with time-resolved frequency offset corrected inversion (TR-FOCI) pulses for labeling and background suppression. We conducted a performance comparison between a parallel transmit (pTx) system equipped with 32 receive (Rx) and 8 transmit (Tx) channels and a standard setup with 32Rx and 2Tx channels. Our findings demonstrate that the pTx system, characterized by a more homogeneous B1 transmit field, resulted in a significantly higher contrast-to-noise ratio, temporal signal-to-noise ratio, and lower coefficient of variance (CoV) than the standard 2Tx setup. Additionally, both setups demonstrated comparable capabilities for functional mapping of the hand region in the motor cortex, achieving reliable results within a short acquisition time of approximately 5 minutes.

Authors 5

1. Icaro Agenor Ferreira de Oliveira corresponding

   Netherlands Institute for Neuroscience · University Health Network · Spinoza Centre for Neuroimaging · Krembil Brain Institute

   Affiliation as printed

   Computational Cognitive Neuroscience and Neuroimaging, Netherlands Institute for Neuroscience, Amsterdam, Netherlands

   Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada

   Spinoza Centre for Neuroimaging, Netherlands Academy for Arts and Sciences, Amsterdam, Netherlands

2. Robin Schnabel

   Spinoza Centre for Neuroimaging

   Affiliation as printed

   Spinoza Centre for Neuroimaging, Netherlands Academy for Arts and Sciences, Amsterdam, Netherlands

3. Matthias J.P. van Osch Aachen C.J. Gorter MRI Center Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands

4. Wietske van der Zwaag

   Netherlands Institute for Neuroscience · Spinoza Centre for Neuroimaging

   Affiliation as printed

   Computational Cognitive Neuroscience and Neuroimaging, Netherlands Institute for Neuroscience, Amsterdam, Netherlands

   Spinoza Centre for Neuroimaging, Netherlands Academy for Arts and Sciences, Amsterdam, Netherlands

5. Lydiane Hirschler Aachen C.J. Gorter MRI Center Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands