Evaluation of currents induced in the heart as a consequence of standing in strong static magnetic field

Danilo Mureddu, Simona Valbonesi, Ermanno Papotti, Andrea Vanore, Marina Barbiroli

Abstract


In the last few years we have been watching a remarkable development of technologies using high density static magnetic
fields in industry and medicine. In medical environment the diagnostic use of Magnetic Resonance (MR) has become
the Gold Standard to identify a great number of pathologies. The increase of static magnetic field intensity levels,
besides the equipment resolution’s gain and the application fields widening, has led to a substantial decrease of clinical
examination duration with economic benefits and better comforts for the patient. On the other hand we have witnessed
an increase of problems connected with the exposure to high density static magnetic fields. This work focuses
on the research of a model thought to evaluate currents induced within the heart, as a consequence of the exposure to
the static magnetic field produced by a Magnetic Resonance scanner; such induced currents, when too high, could have
negative effects on heart’s electric conduction. Starting from a simplified modelling of the heart and making detailed
measurements of the static magnetic field, we propose a mathematical model for the evaluation of electric currents induced
within the heart by static magnetic field, as a consequence of the blood flowing within the arteries and within the
heart chambers. Such currents, provoked only by the standing of a patient in a strong static magnetic field, are not avoidable
and could be the cause of some heart problems described in medical literature and denounced by patients exposed
to static fields above 7.0 T, for diagnostic reasons. Moreover the heart is extremely sensitive to external currents, so
currents induced at an intensity higher than physiological levels could cause malfunctions to the electrical conduction
of the organ.


Keywords


MRI; magnetic static field; induced current; heart

Full Text:

PDF

References


Amendment to the Icnirp Statement on Medical Magnetic Resonance (MR) Procedures: Protection of Patients, 2009. Health Physics 97 (3):5, 259 - 261.

Decreto Legislativo 9 aprile 2008, n.81, Attuazione dell’articolo 1 della legge 3 agosto 2007, n.123, in materia di tutela della salute e dellasicurezza nei luoghi di lavoro.

Direttiva 2004/40/CE del Parlamento Europeo e del Consiglio del 29 aprile 2004 sulle prescrizioni minime di sicurezza e di salute relative all’esposizione dei lavoratori ai rischi derivanti dagli agenti fisici (campi elettromagnetici) (diciottesima direttiva particolare ai sensi dell’articolo 16, paragrafo 1, della direttiva 89/391/CEE), Gazzetta ufficiale dell’Unione europea.

Direttiva 2013/35/UE del Parlamento Europeo e del Consiglio del 26 giugno 2013 sulle disposizioni minime di sicurezza e di salute relative all’esposizione dei lavoratori ai rischi derivanti dagli agenti fisici (campi elettromagnetici) (ventesima direttiva particolare ai sensi dell’articolo 16, paragrafo 1, della direttiva 89/391/CEE) e che abroga la direttiva 2004/40/CE.

Gray, H., 1978. Antomia del Gray vol. 1, Zanichelli, Bologna.

Grissom, C., 1995. “Magnetic field effects in biology-a survey of possible mechanisms with emphasis on radical-pair recombination”. Chemical Reviews, 95, 3 - 24.

Guidelines on Limits of Exposure to Static Magnetic Fields, 2009. Health Physics, 96 (4), 504 - 514.

Holden, A., 2005. “The sensitivity of the heart to static magnetic fields”. Progress in biophysics and molecular biology, vol. 87, no. 2-3, pp. 289.

Kanal, E., Gillen, J., Evans, J., Savitz, D., Shellock, F., 1993. “Survey of reproductive health among female mr workers”. Radiol, 187, 395 - 399.

Klinke, R., Silbernagl, S., 1999. Fisiologia vol. 1. Zanichelli, Bologna.

Liu, Y., Edge, R., Henbest, K., Timmel, C., Hore, P., Gast, P., 2005. “Magnetic field effect on singlet oxygen production in a biochemical system”. Chem Commun (Camb), 2, 174 - 176.

Miyakoshi, J., 2005. “Effects of static magnetic fields at the cellular level”. Prog Biophys Mol Biol, 87, 213 - 224.

Netter, F., 2001. Atlante di anatomia umana. Masson.

Shah, N., 2012. “Advances in ultra-high filed mri at 9.4 t and hybrid 3 t mr-pet”. In Presentazione orale al convegno SIF 2012, Sezione IVB Biofisica e fisica medica.

Tenforde, T.S., Budinger, T.F., 1985. “Biological effects and physical safety aspects of nmr imaging and in vivo spectroscopy”. American Association of Physicists in Medicine.

Tenforde, T.S., 2005. “Magnetically induced electric fields and currents in the circulatory system”. Progress in Biophysics and Molecular Biology, 279 - 288.

Weiss, J., Herrick, R., Taber, K., Contant, C., Plishker, G., 1992. “Bio-effects of high magnetic fields: a study using a simple animal model”. Magn Reson Imaging, 10, 689 - 694.


Refbacks

  • There are currently no refbacks.




Copyright (c) 2015 Italian Journal of Occupational and Environmental Hygiene

© 2015 IJOEHY eISSN: 2464-8817 Associazione Italiana degli Igienisti Industriali |