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Motion-robust cardiac B1+ mapping at 3T using interleaved bloch-siegert shifts
| Content Provider | Scilit |
|---|---|
| Author | Weingärtner, Sebastian Zimmer, Fabian Metzger, Gregory J. Uğurbil, Kâmil de Moortele, Pierre-Francois Van Akçakaya, Mehmet |
| Copyright Year | 2016 |
| Description | Journal: Magnetic Resonance in Medicine To develop and evaluate a robust motion-insensitive Bloch-Siegert shift based B1+ mapping method in the heart. Cardiac Bloch-Siegert B1+ mapping was performed with interleaved positive and negative off-resonance shifts and diastolic spoiled gradient echo imaging in 12 heartbeats. Numerical simulations were performed to study the impact of respiratory motion. The method was compared with three-dimensional (3D) actual flip angle imaging (AFI) and two-dimensional (2D) saturated double angle method (SDAM) in phantom scans. Cardiac B1+ maps of three different views were acquired in six healthy volunteers using Bloch-Siegert and SDAM during breath-hold and free breathing. In vivo maps were evaluated for inter-view consistency using the correlation coefficients of the B1+ profiles along the lines of intersection between the views. For the Bloch-Siegert sequence, numerical simulations indicated high similarity between breath-hold and free breathing scans, and phantom results indicated low deviation from the 3D AFI reference (normalized root mean square error [NRMSE] = 2.0%). Increased deviation was observed with 2D SDAM (NRMSE = 5.0%) due to underestimation caused by imperfect excitation slice profiles. Breath-hold and free breathing Bloch-Siegert in vivo B1+ maps were visually comparable with no significant difference in the inter-view consistency (P > 0.36). SDAM showed strongly impaired B1+ map quality during free breathing. Inter-view consistency was significantly lower than with the Bloch-Siegert method (breath-hold: P = 0.014, free breathing: P < 0.0001). The proposed interleaved Bloch-Siegert sequence enables cardiac B1+ mapping with improved inter-view consistency and high resilience to respiratory motion. Magn Reson Med 78:670-677, 2017. © 2016 International Society for Magnetic Resonance in Medicine. |
| Related Links | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5340643/pdf |
| Ending Page | 677 |
| Page Count | 8 |
| Starting Page | 670 |
| e-ISSN | 15222594 |
| DOI | 10.1002/mrm.26395 |
| Journal | Magnetic Resonance in Medicine |
| Issue Number | 2 |
| Volume Number | 78 |
| Language | English |
| Publisher | Wiley-Blackwell |
| Publisher Date | 2016-09-07 |
| Access Restriction | Open |
| Subject Keyword | Journal: Magnetic Resonance in Medicine Radiology, Nuclear Medicine and Imaging B1+ Mapping; Bloch-siegert Shift; Motion Robustness Abdominal Imaging Cardiac Imaging |
| Content Type | Text |
| Resource Type | Article |
