| Zugriffsnummer | 45333 |
| Dokumenttyp | Zeitschriftenartikel |
| Peer Review | mit Peer Review |
| Sprache | Englisch |
| Titel | 3D Free-breathing multichannel absolute B+1 mapping in the human body at 7T |
| Autor(in); Institution |
Dietrich, Sebastian; 8.1, Biomedizinische Magnetresonanz, PTB-Berlin
Aigner, Christoph Stefan; 8.1, Biomedizinische Magnetresonanz, PTB-Berlin
Kolbitsch, Christoph; 8.1, Biomedizinische Magnetresonanz, PTB-Berlin
Mayer, Johannes; 8.1, Biomedizinische Magnetresonanz, PTB-Berlin
Ludwig, Juliane; 8.1, Biomedizinische Magnetresonanz, PTB-Berlin
Schmidt, Simon; Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, GERMANY
Schäffter, Tobias; 8, Medizinphysik und metrologische Informationstechnik, PTB-Berlin
Schmitter, Sebastian; 8.1, Biomedizinische Magnetresonanz, PTB-Berlin
|
| Quelle/Jahr | Magnetic Resonance in Medicine: 85 (2021), 5, 2552 - 2567 |
| ISSN | 0740-3194 (PRINT) ; 1522-2594 (ONLINE) |
| DOI | |
| Verlag | London: Wiley |
| Freie Schlagworte | 7 Tesla ; actual flip angle imaging ; body imaging ; B+1 mapping ; radial phase encoding ; ultrahigh field |
| Zusammenfassung | Purpose: To introduce and investigate a method for free-breathing three-dimensional (3D) B+1 mapping of the human body at ultrahigh field (UHF), which can be used to generate homogenous flip angle (FA) distributions in the human body at UHF. Methods: A 3D relative B+1 mapping sequence with a radial phase-encoding (RPE) k-space trajectory was developed and applied in 11 healthy subjects at 7T. An RPEbased actual flip angle mapping method was applied with a dedicated B+1 shim setting to calibrate the relative B+1 maps yielding absolute B+1 maps of the individual transmit channels. The method was evaluated in a motion phantom and by multidimensional in vivo measurements. Additionally, 3D gradient echo scans with and without static phase-only B+1 shims were used to qualitatively validate B+1 shim predictions. Results: The phantom validation revealed good agreement for B+1 maps between dynamicmeasurement and static reference acquisition. The proposed 3D method was successfully validated in vivo by comparing magnitude and phase distributions with a 2D Cartesian reference. 3D B+1 maps free from visible motion artifacts were successfully acquired for 11 subjects with body mass indexes ranging from 19 kg/m2 to 34 kg/m2 . 3D respirationresolved absolute B+1 maps indicated FA differences between inhalation and exhalation up to 15% for one channel and up to 24% for combined channels for shallow breathing. Conclusion: The proposed method provides respiration-resolved absolute 3D B+1 maps of the human body at UHF, which enables the investigation and development of 3D B+1shimming and parallel transmission methods to further enhance body imaging at UHF. |
| Kostenfreier Zugang | Open Access Hybrid |
| Rechteinformation | CC BY 4.0 ; Creative Commons Attribution 4.0 License |
| Themenbereich der Metrologie | Metrologie in der Medizin |
| Förderinformationen (1) |
Förderername: Deutsche Forschungsgemeinschaft (DFG)
Förderer ID: 0000 0001 2096 9829 Förderer ID Typ: ISNI Förderprogramm: Grant/Award Nr SCHM 2677/2-1 ; GRK2260 BIOQIC |
Zitierung
Dietrich, S., Aigner, C. S., Kolbitsch, C., Mayer, J., Ludwig, J., Schmidt, S., Schäffter, T., & Schmitter, S. (2021). 3D Free-breathing multichannel absolute B⁺₁ mapping in the human body at 7T. Magnetic Resonance in Medicine, 85(5), 2552–2567. https://doi.org/10.1002/mrm.28602