| Zugriffsnummer | 46976 |
| Dokumenttyp | Zeitschriftenartikel |
| Peer Review | mit Peer Review |
| Sprache | Englisch |
| Titel | Hybrid B1+-shimming and gradient adaptions for improved pseudo-continuous arterial spin labeling at 7 Tesla |
| Autor(in); Institution |
Meixner, C.; Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, GERMANY
Eisen, C.; Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
Schmitter, Sebastian; 8.1, Biomedizinische Magnetresonanz, PTB-Berlin
Müller, M.; Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
Herrler, J.; Department of Neuroradiology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
Hensel, B.; Center for Medical Physics and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
Dörfler, A; Department of Neuroradiology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, GERMANY
Uder, M.; Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, GERMANY
Nagel, A.; Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, GERMANY; Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, GERMANY; Institute of Medical Physics, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, GERMANY
|
| Quelle/Jahr | Magnetic Resonance Imaging: 87 (2022), 1, 207 - 219 |
| ISSN | 0730-725X |
| DOI | |
| Verlag | Wiley |
| Freie Schlagworte | 7 Tesla ; B1 shimming ; pcASL ; pTx ; Ultra-high field strenths ; VERSE |
| Zusammenfassung | Purpose: To improve pseudo- continuous arterial spin labeling (pcASL) at 7T by exploiting a hybrid homogeneity- and efficiency- optimized B+1-shim with adapted gradient strength as well as background suppression. Methods: The following three experiments were performed at 7T, each employ-ing five volunteers: (1) A hybrid (ie, homogeneity- efficiency optimized) B+1-shim was introduced and evaluated for variable- rate selective excitation pcASL labeling. Therefore, B+1- maps in the V3 segment and time- of- flight images were acquired to identify the feeding arteries. For validation, a gradient- echo sequence was applied in circular polarized (CP) mode and with the hybrid B+1-shim. Additionally, the gray matter (temporal) signal- to- noise ratio (tSNR) in pcASL perfusion images was eval-uated. (2) Bloch simulations for the pcASL labeling were conducted and validated experimentally, with a focus on the slice- selective gradients. (3) Background sup-pression was added to the B+1-shimmed, gradient- adapted 7T sequence and this was then compared to a matched sequence at 3T. Results: The B+1-shim improved the signal within the labeling plane (23.6%) and the SNR/tSNR increased (+11%/+11%) compared to its value in CP mode; however, the increase was not significant. In accordance with the simulations, the adapted gradients increased the tSNR (35%) and SNR (45%) significantly. Background suppression further improved the perfusion images at 7T, and this protocol performed as well as a resolution- matched protocol at 3T. Conclusion: The combination of the proposed hybrid B+1-phase- shim with the adapted slice- selective gradients and background suppression shows great potential for improved pcASL labeling under suboptimal B+1 conditions at 7T |
| Kostenfreier Zugang | Open Access Hybrid |
| Rechteinformation | CC BY 4.0 ; Creative Commons Attribution 4.0 License |
| Themenbereich der Metrologie | Metrologie in der Medizin |
Zitierung
Meixner, C., Eisen, C., Schmitter, S., Müller, M., Herrler, J., Hensel, B., Dörfler, A., Uder, M., & Nagel, A. (2022). Hybrid B1+-shimming and gradient adaptions for improved pseudo-continuous arterial spin labeling at 7 Tesla. Magnetic Resonance Imaging, 87(1), 207–219. https://doi.org/10.1002/mrm.28982