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Hu X, Chen X, Liu X, Zheng H, Li Y, Zhang X. Parallel imaging performance investigation of an 8-channel common-mode differential-mode (CMDM) planar array for 7T MRI. Quant Imaging Med Surg 2014; 4:33-42. [PMID: 24649433 DOI: 10.3978/j.issn.2223-4292.2014.02.05] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 02/24/2014] [Indexed: 11/14/2022]
Abstract
An 8-channel planar phased array was proposed based on the common-mode differential-mode (CMDM) structure for ultrahigh field MRI. The parallel imaging performance of the 8-channel CMDM planar array was numerically investigated based on electromagnetic simulations and Cartesian sensitivity encoding (SENSE) reconstruction. The signal-to-noise ratio (SNR) of multichannel images combined using root-sum-of-squares (rSoS) and covariance weighted root-sum-of-squares (Cov-rSoS) at various reduction factors were compared between 8-channel CMDM array and 4-channel CM and DM array. The results of the study indicated the 8-channel CMDM array excelled the 4-channel CM and DM in SNR. The g-factor maps and artifact power were calculated to evaluate parallel imaging performance of the proposed 8-channel CMDM array. The artifact power of 8-channel CMDM array was reduced dramatically compared with the 4-channel CM and DM arrays demonstrating the parallel imaging feasibility of the CMDM array.
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Affiliation(s)
- Xiaoqing Hu
- 1 Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology of Chinese Academy of Sciences, Shenzhen 518055, China ; 2 Shenzhen Key Laboratory for MRI, Shenzhen 518055, China ; 3 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA ; 4 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA
| | - Xiao Chen
- 1 Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology of Chinese Academy of Sciences, Shenzhen 518055, China ; 2 Shenzhen Key Laboratory for MRI, Shenzhen 518055, China ; 3 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA ; 4 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA
| | - Xin Liu
- 1 Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology of Chinese Academy of Sciences, Shenzhen 518055, China ; 2 Shenzhen Key Laboratory for MRI, Shenzhen 518055, China ; 3 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA ; 4 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA
| | - Hairong Zheng
- 1 Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology of Chinese Academy of Sciences, Shenzhen 518055, China ; 2 Shenzhen Key Laboratory for MRI, Shenzhen 518055, China ; 3 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA ; 4 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA
| | - Ye Li
- 1 Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology of Chinese Academy of Sciences, Shenzhen 518055, China ; 2 Shenzhen Key Laboratory for MRI, Shenzhen 518055, China ; 3 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA ; 4 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA
| | - Xiaoliang Zhang
- 1 Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology of Chinese Academy of Sciences, Shenzhen 518055, China ; 2 Shenzhen Key Laboratory for MRI, Shenzhen 518055, China ; 3 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA ; 4 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA
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Li Y, Pang Y, Vigneron D, Glenn O, Xu D, Zhang X. Investigation of multichannel phased array performance for fetal MR imaging on 1.5T clinical MR system. Quant Imaging Med Surg 2011; 1:24-30. [PMID: 22408747 PMCID: PMC3298443 DOI: 10.3978/j.issn.2223-4292.2011.11.04] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 11/15/2011] [Indexed: 11/14/2022]
Abstract
Fetal MRI on 1.5T clinical scanner has been increasingly becoming a powerful imaging tool for studying fetal brain abnormalities in vivo. Due to limited availability of dedicated fetal phased arrays, commercial torso or cardiac phased arrays are routinely used for fetal scans, which are unable to provide optimized SNR and parallel imaging performance with a small number coil elements, and insufficient coverage and filling factor. This poses a demand for the investigation and development of dedicated and efficient radiofrequency (RF) hardware to improve fetal imaging. In this work, an investigational approach to simulate the performance of multichannel flexible phased arrays is proposed to find a better solution to fetal MR imaging. A 32 channel fetal array is presented to increase coil sensitivity, coverage and parallel imaging performance. The electromagnetic field distribution of each element of the fetal array is numerically simulated by using finite-difference time-domain (FDTD) method. The array performance, including B(1) coverage, parallel reconstructed images and artifact power, is then theoretically calculated and compared with the torso array. Study results show that the proposed array is capable of increasing B(1) field strength as well as sensitivity homogeneity in the entire area of uterus. This would ensure high quality imaging regardless of the location of the fetus in the uterus. In addition, the paralleling imaging performance of the proposed fetal array is validated by using artifact power comparison with torso array. These results demonstrate the feasibility of the 32 channel flexible array for fetal MR imaging at 1.5T.
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Affiliation(s)
- Ye Li
- Department of Radiology and Biomedical Imaging, University of California San Francisco, USA;
| | - Yong Pang
- Department of Radiology and Biomedical Imaging, University of California San Francisco, USA;
| | - Daniel Vigneron
- Department of Radiology and Biomedical Imaging, University of California San Francisco, USA;
- UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA
| | - Orit Glenn
- Department of Radiology and Biomedical Imaging, University of California San Francisco, USA;
| | - Duan Xu
- Department of Radiology and Biomedical Imaging, University of California San Francisco, USA;
| | - Xiaoliang Zhang
- Department of Radiology and Biomedical Imaging, University of California San Francisco, USA;
- UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA
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