Work

SNR ‐efficient whole‐brain pseudo‐continuous arterial spin labeling perfusion imaging at 7 T

Year: 2025

Type: article

Abstract: Purpose To optimize pseudo-continuous arterial spin labeling (PCASL) parameters to maximize SNR efficiency for RF power constrained whole brain perfusion imaging at 7 T. Methods We used Bloch simulations of pulsatile laminar flow to optimize the PCASL parameters for maximum SNR efficiency, balancing labeling efficiency and total RF power. The optimization included adjusting the inter-RF pulse spacing (TR PCASL ), mean B 1 + (B 1 ave ), slice-selective gradient amplitude (G max ), and mean gradient amplitude (G ave ). In vivo data were acquired from four volunteers at 7 T to validate the optimized parameters. Dynamic B 0 -shimming and flip angle adjustments were utilized to avoid needing to make the PCASL parameters robust to B 0 /B 1 + variations. Results The optimized PCASL parameters achieved a significant (3.1x) reduction in RF power while maintaining high labeling efficiency. This allowed for longer label durations and minimized deadtime, and resulted in a 126% improvement in SNR efficiency in vivo compared to a previously proposed protocol. Additionally, the static tissue response was improved, reducing the required distance between labeling plane and imaging volume. Conclusion These optimized PCASL parameters provide a robust and efficient approach for whole brain perfusion imaging at 7 T, with significant improvements in SNR efficiency and reduced SAR burden.

Source: Magnetic Resonance in Medicine

DOI: 10.1002/mrm.30527

Authors: Joseph G. Woods, Yang Ji, Hongwei Li, Aaron T. Hess, Thomas W. Okell

Institutions: University of Oxford, Wellcome Centre for Integrative Neuroimaging, University of Science and Technology of China, Shanghai Medical College of Fudan University, Fudan University

Language: English

Topic: Advanced MRI Techniques and Applications

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,680