| Zugriffsnummer | 40272 |
| Dokumenttyp | Zeitschriftenartikel |
| Peer Review | mit Peer Review |
| Sprache | Englisch |
| Titel | High peak and high average radiofrequency power transmit/receive switch for thermal magnetic resonance |
| Autor(in); Institution |
Ji, Y.; Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, GERMANY
Hoffmann, Werner; 8.1, Biomedizinische Magnetresonanz, PTB-Berlin
Pham, M.; Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, GERMANY
Dunn, A. E.; School of Chemical Engineering, The University of South New Wales, Sydney, AUSTRALIA
Han, H.; Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, GERMANY
Özerdem, C.; Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, GERMANY
Waiczies, H.; MRI.TOOLS GmbH, Berlin, GERMANY
Rohloff, M.; Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, GERMANY
Endemann, B.; Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, GERMANY
Boyer, C.; School of Chemical Engineering, The University of South New Wales, Sydney, AUSTRALIA
Lim, M.; School of Chemical Engineering, The University of South New Wales, Sydney, AUSTRALIA
Niendorf, T.; Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, GERMANY; Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, GERMANY
Winter, L.; Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, GERMANY
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| Quelle/Jahr | Magnetic Resonance in Medicine: 80 (2018), 5, 2246 - 2255 |
| ISSN | 0740-3194 (PRINT) ; 1522-2594 (ONLINE) |
| DOI | |
| Verlag | Wiley-Blackwell |
| Freie Schlagworte | open source hardware ; RF induced heating ; thermal magnetic resonance ; transmit receive switch |
| Zusammenfassung | Purpose To study the role of temperature in biological systems, diagnostic contrasts and thermal therapies, RF pulses for MR spin excitation can be deliberately used to apply a thermal stimulus. This application requires dedicated transmit/receive (Tx/Rx) switches that support high peak powers for MRI and high average powers for RF heating. To meet this goal, we propose a high‐performance Tx/Rx switch based on positive‐intrinsic‐negative diodes and quarter‐wavelength (λ/4) stubs. Methods The λ/4 stubs in the proposed Tx/Rx switch design route the transmitted RF signal directly to the RF coil/antenna without passing through any electronic components (e.g., positive‐intrinsic‐negative diodes). Bench measurements, MRI, MR thermometry, and RF heating experiments were performed at f = 297 MHz (B0 = 7 T) to examine the characteristics and applicability of the switch. Results The proposed design provided an isolation of −35.7dB/−41.5dB during transmission/reception. The insertion loss was −0.41dB/−0.27dB during transmission/reception. The switch supports high peak (3.9 kW) and high average (120 W) RF powers for MRI and RF heating at f = 297 MHz. High‐resolution MRI of the wrist yielded image quality competitive with that obtained with a conventional Tx/Rx switch. Radiofrequency heating in phantom monitored by MR thermometry demonstrated the switch applicability for thermal modulation. Upon these findings, thermally activated release of a model drug attached to thermoresponsive polymers was demonstrated. Conclusion The high‐power Tx/Rx switch enables thermal MR applications at 7 T, contributing to the study of the role of temperature in biological systems and diseases. All design files of the switch will be made available open source at www.opensourceimaging.org. www.opensourceimaging.org/project/thermal-mr-tr-switch/ |
Zitierung
Ji, Y., Hoffmann, W., Pham, M., Dunn, A. E., Han, H., Özerdem, C., Waiczies, H., Rohloff, M., Endemann, B., Boyer, C., Lim, M., Niendorf, T., & Winter, L. (2018). High peak and high average radiofrequency power transmit/receive switch for thermal magnetic resonance. Magnetic Resonance in Medicine, 80(5), 2246–2255. https://doi.org/10.1002/mrm.27194