Purpose: To evaluate the feasibility of quantitative single breath-hold renal arterial spin labeling (ASL) imaging at 7T. Methods: A single-shot fast spin echo FAIR (flow-sensitive alternating inversion recovery) method was used to perform two studies. First, a multi-delay perfusion study was performed to estimate the spin labeling temporal bolus width achievable with a local transceiver array coil at 7T. Second, with a conservatively defined bolus width, a quantitative perfusion study was performed using the single subtraction approach. To address issues of (Formula presented.) inhomogeneity/efficiency and excessive short-term specific absorption rates, various strategies were used, such as dynamic radiofrequency shimming and optimization. Results: A conservative temporal bolus width of 600 ms determined from the multi-delay study was applied for single-subtraction imaging to measure the renal blood flow in the cortex and medulla: 303 ± 31.8 and 91.3 ± 15.2 (mL/100 g/min), respectively. The estimated spatial and temporal signal-to-noise ratios of renal perfusion measurements were 3.8 ± 0.7 and 2.4 ± 0.6 for the cortex, and 2.2 ± 0.6 and 1.4 ± 0.2 for the medulla. Conclusion: With proper management of field strength specific challenges, quantitative renal ASL imaging can be achieved at 7T within a single breath-hold. Magn Reson Med 79:815–825, 2018.
Bibliographical noteFunding Information:
Research reported in this publication was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health Award UL1TR000114 in addition to other sources. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
© 2017 International Society for Magnetic Resonance in Medicine
Copyright 2020 Elsevier B.V., All rights reserved.
- arterial spin labeling (ASL)
- magnetic resonance imaging (MRI)
- renal perfusion or renal blood flow (RBF)
- ultrahigh field (UHF)