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

Publication date: Aug 26, 2024

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.

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Concepts Keywords
Field Arterial
Inhomogeneities Asl
Mri Coil
Reliable Field
Uhf Imaging
Inversion
Labeling
Mri
Parallel
Perfusion
Ptx
Spin
Temporal
Transmit
Uhf

Semantics

Type Source Name
disease VO time
disease VO frequency
disease VO Canada
drug DRUGBANK Coenzyme M
drug DRUGBANK Water
disease IDO blood
disease IDO history
disease IDO process
disease VO efficiency
disease MESH sti
disease VO protocol
drug DRUGBANK Flunarizine
disease VO USA
disease VO volume
disease VO Gap
disease VO effective
drug DRUGBANK Trestolone
drug DRUGBANK Vildagliptin
drug DRUGBANK Ranitidine

Original Article

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