Robin Etzel1,2, Choukri Mekkaoui3,4, Ekaterina S Ivshina5, Timothy G Reese3,4, David E Sosnovik3,4,6,7,8, Sam-Luca J D Hansen1, Anpreet Ghotra1, Nicolas Kutscha1, Chaimaa Chemlali1, Lawrence L Wald3,4,8, Andreas H Mahnken2, Boris Keil1,9. 1. Institute of Medical Physics and Radiation Protection, TH Mittelhessen University of Applied Sciences, Giessen, Germany. 2. Clinic of Diagnostic and Interventional Radiology, Philipps-University of Marburg, Marburg, Germany. 3. Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, USA. 4. Harvard Medical School, Boston, Massachusetts, USA. 5. Princeton University, Princeton, New Jersey, USA. 6. Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, Massachusetts, USA. 7. Cardiology Division, Massachusetts General Hospital, Boston, Massachusetts, USA. 8. Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts, USA. 9. Center for Mind, Brain and Behavior (CMBB), Marburg, Germany.
Abstract
PURPOSE: Three 64-channel cardiac coils with different detector array configurations were designed and constructed to evaluate acceleration capabilities in simultaneous multislice (SMS) imaging for 3T cardiac MRI. METHODS: Three 64-channel coil array configurations obtained from a simulation-guided design approach were constructed and systematically evaluated regarding their encoding capabilities for accelerated SMS cardiac acquisitions at 3T. Array configuration AUni-sized consists of uniformly distributed equally sized loops in an overlapped arrangement, BGapped uses a gapped array design with symmetrically distributed equally sized loops, and CDense has non-uniform loop density and size, where smaller elements were centered over the heart and larger elements were placed surrounding the target region. To isolate the anatomic variation from differences in the coil configurations, all three array coils were built with identical semi-adjustable housing segments. The arrays' performance was compared using bench-level measurements and imaging performance tests, including signal-to-noise ratio (SNR) maps, array element noise correlation, and SMS acceleration capabilities. Additionally, all cardiac array coils were evaluated on a healthy volunteer. RESULTS: The array configuration CDense with the non-uniformly distributed loop density showed the best overall cardiac imaging performance in both SNR and SMS encoding power, when compared to the other constructed arrays. The diffusion weighted cardiac acquisitions on a healthy volunteer support the favorable accelerated SNR performance of this array configuration. CONCLUSION: Our results indicate that optimized highly parallel cardiac arrays, such as the 64-channel coil with a non-uniform loop size and density improve highly accelerated SMS cardiac MRI in comparison to symmetrically distributed loop array designs.
PURPOSE: Three 64-channel cardiac coils with different detector array configurations were designed and constructed to evaluate acceleration capabilities in simultaneous multislice (SMS) imaging for 3T cardiac MRI. METHODS: Three 64-channel coil array configurations obtained from a simulation-guided design approach were constructed and systematically evaluated regarding their encoding capabilities for accelerated SMS cardiac acquisitions at 3T. Array configuration AUni-sized consists of uniformly distributed equally sized loops in an overlapped arrangement, BGapped uses a gapped array design with symmetrically distributed equally sized loops, and CDense has non-uniform loop density and size, where smaller elements were centered over the heart and larger elements were placed surrounding the target region. To isolate the anatomic variation from differences in the coil configurations, all three array coils were built with identical semi-adjustable housing segments. The arrays' performance was compared using bench-level measurements and imaging performance tests, including signal-to-noise ratio (SNR) maps, array element noise correlation, and SMS acceleration capabilities. Additionally, all cardiac array coils were evaluated on a healthy volunteer. RESULTS: The array configuration CDense with the non-uniformly distributed loop density showed the best overall cardiac imaging performance in both SNR and SMS encoding power, when compared to the other constructed arrays. The diffusion weighted cardiac acquisitions on a healthy volunteer support the favorable accelerated SNR performance of this array configuration. CONCLUSION: Our results indicate that optimized highly parallel cardiac arrays, such as the 64-channel coil with a non-uniform loop size and density improve highly accelerated SMS cardiac MRI in comparison to symmetrically distributed loop array designs.
Authors: Ehud J Schmidt; Gregory Olson; Junichi Tokuda; Akbar Alipour; Ronald D Watkins; Eric M Meyer; Hassan Elahi; William G Stevenson; Jeffrey Schweitzer; Charles L Dumoulin; Thomas Johnson; Aravindan Kolandaivelu; Wolfgang Loew; Henry R Halperin Journal: Magn Reson Med Date: 2022-02-10 Impact factor: 3.737