| Autor: |
Sascha, Brunheim, Marcel, Gratz, Sören, Johst, Andreas K, Bitz, Thomas M, Fiedler, Mark E, Ladd, Harald H, Quick, Stephan, Orzada |
| Rok vydání: |
2017 |
| Předmět: |
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| Zdroj: |
Magnetic resonance in medicine. 79(5) |
| ISSN: |
1522-2594 |
| Popis: |
Current methods for mitigation of transmit field B1+ inhomogeneities at ultrahigh field (UHF) MRI by multi-channel radiofrequency (RF) shimming rely on accurate B1+ mapping. This can be time consuming when many RF channels have to be mapped for in vivo body MRI, where the BThe performance of this technique is validated against an established method (DREAM) in phantom measurements for a cylindrical head phantom with an 8-channel transmit/receive (Tx/Rx) array. Furthermore, measurements for a 32-channel Tx/Rx remote array are conducted in a large body phantom and the |B1+| map reliability is validated against simulations of the transmit RF field distribution. Finally, in vivo results of this new mapping technique for human abdomen are presented.For the head phantom (8-channel Tx/Rx coil), the single |B1+| comparison between BThe results demonstrate the potential to acquire 32 accurate single-channel B1+ maps for large field-of-view body imaging within only a single breath-hold of 16 s at 7T UHF MRI. Magn Reson Med 79:2652-2664, 2018. © 2017 International Society for Magnetic Resonance in Medicine. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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