Exposure of Infants to Gradient Fields in a Baby MRI Scanner.
MRI
baby gradient coils
electric fields
exposure
infants
Journal
Bioelectromagnetics
ISSN: 1521-186X
Titre abrégé: Bioelectromagnetics
Pays: United States
ID NLM: 8008281
Informations de publication
Date de publication:
Feb 2022
Feb 2022
Historique:
revised:
14
12
2021
received:
14
02
2021
accepted:
24
12
2021
pubmed:
11
1
2022
medline:
28
1
2022
entrez:
10
1
2022
Statut:
ppublish
Résumé
In pediatric magnetic resonance imaging (MRI), infants are exposed to rapid, time-varying gradient magnetic fields, leading to electric fields induced in the body of infants and potential safety risks (e.g. peripheral nerve stimulation). In this numerical study, the in situ electric fields in infants induced by small-sized gradient coils for a 1.5 T MRI scanner were evaluated. The gradient coil set was specially designed for the efficient imaging of infants within a small-bore (baby) scanner. The magnetic flux density and induced electric fields by the small x, y, z gradient coils in an infant model (8-week-old with a mass of 4.3 kg) were computed using the scalar potential finite differences method. The gradient coils were driven by a 1 kHz sinusoidal waveform and also a trapezoidal waveform with a 250 µs rise time. The model was placed at different scan positions, including the head area (position I), chest area (position II), and body center (position III). It was found that the induced electric fields in most tissues exceeded the basic restrictions of the ICNIRP 2010 guidelines for both waveforms. The electric fields were similar in the region of interest for all coil types and model positions but different outside the imaging region. The y-coil induced larger electric fields compared with the x- and z- coils. Bioelectromagnetics. 43:69-80, 2022. © 2021 Bioelectromagnetics Society.
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
69-80Informations de copyright
© 2021 Bioelectromagnetics Society.
Références
Bakker J, Paulides M, Neufeld E, Christ A, Chen X, Kuster N, Van, Rhoon G. 2012. Children and adults exposed to low-frequency magnetic fields at the ICNIRP reference levels: theoretical assessment of the induced electric fields. Phys Med Biol 57:1815-29.
Canova A, Freschi F, Giaccone L, Manca M. 2015. A simplified procedure for the exposure to the magnetic field produced by resistance spot welding guns. IEEE Trans Magn 52:1-4.
Canova A, Freschi F, Giaccone L, Repetto M. 2010a. Exposure of working population to pulsed magnetic fields. IEEE Trans Magn 46:2819-2822.
Canova A, Freschi F, Repetto M. 2010b. Evaluation of workers exposure to magnetic fields. Eur Phys J-Appl Phys 52:2-8.
Chen XL, Benkler S, Chavannes N, De Santis V, Bakker J, Van Rhoon G, Mosig J, Kuster N. 2013. Analysis of human brain exposure to low-frequency magnetic fields: a numerical assessment of spatially averaged electric fields and exposure limits. Bioelectromagnetics 34:375-384.
Commission IEC. 2002. IEC 60601-2-33-Medical Electrical equipment-Part 2-33: Particular requirements for the basic safety and essential performance of magnetic resonance equipment for medical diagnosis.
Davids M, Guérin B, Klein V, Wald LL. 2020. Optimization of MRI gradient coils with explicit peripheral nerve stimulation constraints. IEEE Trans Med Imag 40:129-142.
Davids M, Guérin B, Malzacher M, Schad LR, Wald LL. 2017. Predicting magnetostimulation thresholds in the peripheral nervous system using realistic body models. Sci Rep 7:5316.
Davids M, Guérin B, Vom Endt A, Schad LR, Wald LL. 2019. Prediction of peripheral nerve stimulation thresholds of MRI gradient coils using coupled electromagnetic and neurodynamic simulations. Magn Reson Med 81:686-701.
Dawson TW, Caputa K, Stuchly MA. 2002. Electric fields induced in humans and rodents by 60 Hz magnetic fields. Phys Med Biol 47:2561-2568.
De Santis V, Chen XL, Laakso I, Hirata A. 2015. An equivalent skin conductivity model for low-frequency magnetic field dosimetry. Biomed Phys Eng Express 1:015201.
Diao Y, Gomez-Tames J, Rashed EA, Kavet R, Hirata A. 2019. Spatial averaging schemes of in situ electric field for low-frequency magnetic field exposures. IEEE Access 7:184320-184331.
Dimbylow P. 2005. Development of the female voxel phantom, NAOMI, and its application to calculations of induced current densities and electric fields from applied low frequency magnetic and electric fields. Phy Med Biol 50:1047-1070.
Gabriel C, Gabriel S, Corthout E. 1996a. The dielectric properties of biological tissues: I. Literature survey. Phys Med Biol 41:2231-2249.
Gabriel S, Lau R, Gabriel C. 1996b. The dielectric properties of biological tissues: II. Measurements in the frequency range 10 Hz to 20 GHz. Phys Med Biol 41:2251-2269.
Gabriel S, Lau R, Gabriel C. 1996c. The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues. Phys Med Biol 41:2271-2293.
Giaccone L. 2020. Compliance of non-sinusoidal or pulsed magnetic fields generated by industrial sources with reference to human exposure guidelines; IEEE. 1-6.
Glover P. 2009. Interaction of MRI field gradients with the human body. Phys Med Biol 54:R99.
Hasgall P, Di Gennaro F, Baumgartner C, Neufeld E, Gosselin M, Payne D, Klingenböck A, Kuster N. 2015. IT'IS Database for Thermal and Electromagnetic Parameters of Biological Tissues Version 3.0.
Helmholtz Zentrum München (German Research Center for Environmental Health). Available from https://www.helmholtz-muenchen.de/en/iss/index.html [Last accessed 13 December 2021].
Hirata A, Takano Y, Kamimura Y, Fujiwara O. 2010a. Effect of the averaging volume and algorithm on the in situ electric field for uniform electric-and magnetic-field exposures. Phys Med Biol 55:N243-N252.
Hirata A, Yamazaki K, Hamada S, Kamimura Y, Tarao H, Wake K, Suzuki Y, Hayashi N, Fujiwara O. 2010b. Intercomparison of induced fields in Japanese male model for ELF magnetic field exposures: Effect of different computational methods and codes. Radiat Prot Dosimetry 138:237-244.
IEEE. 2002. IEEE standard for safety levels with respect to human exposure to electromagnetic fields, 0-3 kHz,C95.6-2002, 2002. New York: Institute of Electrical and Electronics Engineers. pp. 43.
Jokela K. 2000. Restricting exposure to pulsed and broadband magnetic fields. Health Phys 79:373-388.
Kheifets L, Repacholi M, Saunders R, Van Deventer E. 2005. The sensitivity of children to electromagnetic fields. Pediatrics 116:e303-e313.
Lee SK, Mathieu JB, Graziani D, Piel J, Budesheim E, Fiveland E, Hardy CJ, Tan ET, Amm B, Foo TKF. 2015. Peripheral nerve stimulation characteristics of an asymmetric head-only gradient coil compatible with a high-channel-count receiver array. Magn Reson Med 76(6):1939-1950.
Laakso I, Hirata A. 2012. Reducing the staircasing error in computational dosimetry of low-frequency electromagnetic fields. Phys Med Biol 57:N25-34.
Lin J, Saunders R, Schulmeister K, Söderberg P, Swerdlow A, Taki M, Veyret B, Ziegelberger G, Repacholi MH, Matthes R. 2010. ICNIRP Guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz to 100 kHz). Health Phys 99:818-836.
Liu F, Zhao H, Crozier S. 2003. On the induced electric field gradients in the human body for magnetic stimulation by gradient coils in MRI. IEEE Trans Biomed Eng 50:804-815.
Liu L, Trakic A, Sanchez Lopez H, Liu F, Crozier S. 2014. An analysis of the gradient-induced electric fields and current densities in human models when situated in a hybrid MRI-LINAC system. Phys Med Biol 59:233-245.
Mao W, Chronik BA, Feldman RE, Smith MB, Collins CM. 2006. Consideration of magnetically-induced and conservative electric fields within a loaded gradient coil. Magn Reson Med 55:1424-1432.
Notay Y. 2010. An aggregation-based algebraic multigrid method. Electr Trans Numer Anal 37:123-146.
Pethig R. 1987. Dielectric properties of body tissues. Clin Phys Physiol Meas 8:5-12.
Protection ICoN-IR. 2003. Guidance on determining compliance of exposure to pulsed and complex non-sinusoidal waveforms below 100 kHz with ICNIRP guidelines. Health Phys 84:383-387.
Protection ICoN-IR. 2004. Medical magnetic resonance (MR) procedures: Protection of patients. Health Phys 87:197-216.
Roemer PB, Rutt BK. 2021. Minimum electric-field gradient coil design: Theoretical limits and practical guidelines. Magn Reson Med 86:569-580.
Roemer PB, Wade T, Alejski A, McKenzie CA, Rutt BK. 2021. Electric field calculation and peripheral nerve stimulation prediction for head and body gradient coils. Magn Reson Med 86:2301-2315.
Samoudi AM, Vermeeren G, Tanghe E, Holen R, Martens L, Josephs W. 2016. Numerically simulated exposure of children and adults to pulsed gradient fields in MRI. J Magn Reson Imaging 44(5):1360-1367.
Sanchez Lopez H, Liu F, Poole M, Crozier S. 2009. Equivalent magnetization current method applied to the design of gradient coils for magnetic resonance imaging. IEEE Trans Magn 45:767-775.
Schmid G, Cecil S, Überbacher R. 2013a. The role of skin conductivity in a low frequency exposure assessment for peripheral nerve tissue according to the ICNIRP 2010 guidelines. Phys Med Biol 58:4703-4716.
Schmid G, Cecil S, Überbacher R. 2013b. The role of skin conductivity in a low frequency exposure assessment for peripheral nerve tissue according to the ICNIRP 2010 guidelines. Phys Med Biol 58:4703-4716.
Schulte RF, Noeske R. 2015. Peripheral nerve stimulation-optimal gradient waveform design. Magn Reson Med 74:518-522.
So PP, Stuchly MA, Nyenhuis JA. 2004. Peripheral nerve stimulation by gradient switching fields in magnetic resonance imaging. IEEE Trans Biomed Eng 51:1907-1914.
Tang F, Liu F, Freschi F, Li Y, Repetto M, Giaccone L, Wang Y, Crozier S. 2016. An improved asymmetric gradient coil design for high-resolution MRI head imaging. Phys Med Biol 61:8875-8889.
Tonti E. 2013. The Mathematical Structure of Classical and Relativistic Physics: New York Springer. pp. 514.
Wang Q, Wang C, Wang H, Wang H, Zhang H, Li Y, Li L, Ni Z, Huang L, Ma Q. 2010. Development of conduction-cooled superconducting magnet for baby imaging. IEEE Trans Appl Supercond 20:726-731.
Zhang B, Yen YF, Chronik BA, McKinnon GC, Schaefer DJ, Rutt BK. 2003. Peripheral nerve stimulation properties of head and body gradient coils of various sizes. Magn Reson Med 50:50-58.
Zhao H, Crozier S, Liu F. 2002. Finite difference time domain (FDTD) method for modeling the effect of switched gradients on the human body in MRI. Magn Reson Med 48:1037-1042.