TY - JOUR
T1 - Advancing 7T perfusion imaging by pulsed arterial spin labeling
T2 - Using a parallel transmit coil for enhanced labeling robustness and temporal SNR
AU - Oliveira, Ícaro Agenor Ferreira
AU - Schnabel, Robin
AU - van Osch, Matthias J P
AU - Zwaag, Wietske van der
AU - Hirschler, Lydiane
N1 - Copyright: © 2024 Oliveira et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2024/8/25
Y1 - 2024/8/25
N2 - 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.
AB - 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.
KW - Spin Labels
KW - Signal-To-Noise Ratio
KW - Humans
KW - Male
KW - Perfusion Imaging/methods
KW - Adult
KW - Female
KW - Magnetic Resonance Imaging/methods
KW - Cerebrovascular Circulation/physiology
KW - Image Processing, Computer-Assisted/methods
U2 - 10.1371/journal.pone.0309204
DO - 10.1371/journal.pone.0309204
M3 - Article
C2 - 39186519
SN - 1932-6203
VL - 19
SP - e0309204
JO - PLoS ONE
JF - PLoS ONE
IS - 8
ER -