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Noetscher GM, Serano P, Wartman WA, Fujimoto K, Makarov SN. Visible Human Project® female surface based computational phantom (Nelly) for radio-frequency safety evaluation in MRI coils. PLoS One 2021; 16:e0260922. [PMID: 34890429 PMCID: PMC8664205 DOI: 10.1371/journal.pone.0260922] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/19/2021] [Indexed: 11/19/2022] Open
Abstract
Quantitative modeling of specific absorption rate and temperature rise within the human body during 1.5 T and 3 T MRI scans is of clinical significance to ensure patient safety. This work presents justification, via validation and comparison, of the potential use of the Visible Human Project (VHP) derived Computer Aided Design (CAD) female full body computational human model for non-clinical assessment of female patients of age 50–65 years with a BMI of 30–36 during 1.5 T and 3 T based MRI procedures. The initial segmentation validation and four different application examples have been identified and used to compare to numerical simulation results obtained using VHP Female computational human model under the same or similar conditions. The first application example provides a simulation-to-simulation validation while the latter three application examples compare with measured experimental data. Given the same or similar coil settings, the computational human model generates meaningful results for SAR, B1 field, and temperature rise when used in conjunction with the 1.5 T birdcage MRI coils or at higher frequencies corresponding to 3 T MRI. Notably, the deviation in temperature rise from experiment did not exceed 2.75° C for three different heating scenarios considered in the study with relative deviations of 10%, 25%, and 20%. This study provides a reasonably systematic validation and comparison of the VHP-Female CAD v.3.0–5.0 surface-based computational human model starting with the segmentation validation and following four different application examples.
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Affiliation(s)
- Gregory M. Noetscher
- Department of Electrical and Computer Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
- NEVA Electromagnetics, LLC, Yarmouth Port, Massachusetts, United States of America
- * E-mail:
| | - Peter Serano
- Ansys, Inc., Canonsburg, Pennsylvania, United States of America
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - William A. Wartman
- Department of Electrical and Computer Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| | - Kyoko Fujimoto
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland, United States of America
| | - Sergey N. Makarov
- Department of Electrical and Computer Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
- NEVA Electromagnetics, LLC, Yarmouth Port, Massachusetts, United States of America
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
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Parsa J, Mohammadzadeh M. Design and fabrication of a new multi-loop saddle coil for 1.5 T MRI. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:114707. [PMID: 31779412 DOI: 10.1063/1.5114813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 10/21/2019] [Indexed: 06/10/2023]
Abstract
Radiofrequency coils provide high-resolution magnetic resonance (MR) imaging of human tissues. A small RF coil produces MR images with a higher resolution compared to the commercial volume MR coils from mass limited samples. Signal to noise ratio (SNR) plays a key role in the optimal design of receiver radiofrequency coils. In this work, we present a three-loop saddle coil suitable for MR imaging of digits of the human body. The geometry of the introduced coil is optimized to achieve the highest SNR. The coil performance is evaluated through comparing the measured SNR maps of the optimal coil derived from MR images of a saline phantom with the corresponding measured SNR maps of a commercial head coil in axial and sagittal slices. Results verify that the image SNR of the introduced coil is 3.4 times higher than that of the head coil and 2 times higher than that of the similar saddle coils represented in the literature recently. To validate the measured results, SNR maps of the introduced saddle and head coils were simulated and their SNR difference was compared with the corresponding measured data of the two coils. Results show that the simulated and measured data are in agreement with less than 11.8% error.
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Affiliation(s)
- J Parsa
- Department of Energy Engineering, Sharif University of Technology, Tehran 1458889694, Iran
| | - M Mohammadzadeh
- Radiation in Medicine Department, Shahid Beheshti University, Tehran 1983969411, Iran
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