title: Optimizing the ICE decoupling element distance to improve monopole antenna arrays for 7 Tesla MRI.
abstract: The induced current elimination (ICE) method has been previously applied to decouple monopole coil arrays in ultrahigh field MRI. However, the method creates low B1+spots near the decoupling elements. In this study, we aim to improve the performance of ICE-decoupled monopole array in human head imaging at 7 Tesla. Eight-channel ICE-decoupled monopole arrays were optimized by varying the position of the decoupling elements. A series of numerical studies were performed using the co-simulation method. In simulation, decoupling performance, quality (Q-) values and transmit field (B1+) were comparatively investigated. In addition, we constructed an optimized ICE-decoupled monopole array and compared its performance with the unoptimized array. The simulation results showed that a good trade-off between decoupling and B1+loss can be obtained when decoupling elements were moved 2.5-cm away from coil elements. This was validated by in-vivo MR imaging using the constructed array. Compared with the unoptimized ICE decoupled monopole array, the optimized array had a more homogeneous transmit field and no dark spots or signal cancellations in the MR images.
authors.affiliation: Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology, Vanderbilt University, Nashville, TN, USA. Electronic address: xinqiang.yan@vanderbilt.edu.
authors.forename: Xinqiang
authors.initials: X
authors.lastname: Yan
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA; UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA.
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Xue
authors.affiliation: Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology, Vanderbilt University, Nashville, TN, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Gore
authors.affiliation: Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA.
authors.forename: William A
authors.initials: WA
authors.lastname: Grissom
mesh_terms: D001921:Brain / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D003198:Computer Simulation; D004867:Equipment Design; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D014159:Transducers
keywords: Decoupling; Homogeneous transmit field; Ice; Magnetic wall; Monopole; Ultrahigh field MRI