EXPERIMENTAL STUDY OF FERROMAGNETIC OBJECTS HEATING DURING MAGNETIC RESONANCE IMAGING

Vasilev Yu.A., Semenov D.S., Yatseev V.A., Akhmad E.S., Petraikin A.V., Marusina M.Ya., Vasileva Yu.N. Experimental study of ferromagnetic objects heating during magnetic resonance imaging. Scientific and Technical Journal of Information Technologies, Mechanics and Optics , 2019, vol. 19, no. 1, pp. 173–179 (in Russian). doi: 10.17586/2226-1494-2019-19-1-173-179

Subject of study. Magnetic resonance imaging (MRI) is one of the most common and popular methods of medical imaging, based on the phenomenon of nuclear magnetic resonance. Despite the absence of ionizing radiation, there are some risk factors for the patient, one of which is the presence of metal structures in the patient's body. The thermal effect arising in the process of magnetic resonance study for patients with ferromagnetic objects is studied. Method. The study of metal objects surface heating was carried out using fiber optic sensors. A phantom was developed with the objects of different materials (steel, ferrite, brass, neodymium magnet) fixed on it. To obtain the maximum possible heating, the corresponding scanning conditions with the highest possible specific absorption coefficient were chosen. Main results. The results of materials heating measuring are presented. It is shown that the temperature of all objects increased in the range of 2.5 to 4.0 °C for total scan time of 90 minutes, while the temperature outside these objects did not change. In this case, heating exceeding the limit of 1 °C for 6 minutes was observed for none of the objects. Practical relevance. The study results can be applied in the development and identification of mathematical models of heat transfer within the framework of comprehensive patient safety in the MRI room. The study opens up the prospect of expanding indications in MRI studies for patients with metallic foreign bodies who need this type of diagnosis (without taking into account other risks: mechanical displacement and deterioration of visualization).

1. Kim S.J., Kim K.A. Safety issues and updates under MR environments. European Journal of Radiology, 2017, vol. 89, pp. 7–13. doi: 10.1016/j.ejrad.2017.01.010
2. ICNIRP. Guidelines for limiting exposure to electric fields induced by movement of the human body in a static magnetic field and by time-varying magnetic fields below 1 Hz. Health Physics, 2014, vol. 106, no. 3, pp. 418–425. doi: 10.1097/hp.0b013e31829e5580
3. Glover P.M. Interaction of MRI field gradients with the human body. Physics in Medical Biology, 2009, vol. 54, no. 21, pp. R99–R115. doi: 10.1088/0031-9155/54/21/R01
4. Formica D., Silvestri S. Biological effects of exposure to magnetic resonance imaging: an overview. BioMedical Engineering Online, 2004, vol. 3, pp. 11. doi: 10.1186/1475-925X-3-11
5. Kanal E. et al. ACR guidance document on MR safe practices: 2013. Journal of Magnetic Resonance Imaging, 2013, vol. 37, no. 3, pp. 501–530. doi: 10.1002/jmri.24011
6. Eshed I. et al. Is magnetic resonance imaging safe for patients with retained metal fragments from combat and terrorist attacks? Acta Radiologica, 2010, vol. 51, no. 2, pp. 170–174. doi: 10.3109/02841850903376298
7. Martinez-del-Campo E. et al. Magnetic resonance imaging in lumbar gunshot wounds: an absolute contraindication? Neurosurgical Focus, 2014, vol. 37, pp. E13. doi: 10.3171/2014.7.focus1496
8. Dedini R.D. et al. MRI issues for ballistic objects: Information obtained at 1.5-, 3- and 7-Tesla. Spine Journal, 2013, vol. 13, no. 7, pp. 815–822. doi: 10.1016/j.spinee.2013.02.068
9. Panych L.P., Madore B. The physics of MRI safety. Journal of Magnetic Resonance Imaging, 2018, vol. 47, no. 1, pp. 28–43. doi: 10.1002/jmri.25761
10. Woods T.O. Guidance for Industry and FDA Staff Establishing Safety and Compatibility of Passive Implants in the Magnetic Resonance (MR) Environment. U.S. Food Drug Adm., 2014, 7 p.
11. Feng D.X. et al. Evaluation of 39 medical implants at 7.0T. The British Journal of Radiology, 2015, vol. 88, no. 1056, pp. 20150633. doi: 10.1259/bjr.20150633
12. Mattei E. et al. Impact of capped and uncapped abandoned leads on the heating of an MR-conditional pacemaker implant. Magnetic Resonance in Medicine, 2015, vol. 73, no. 1, pp. 390–400. doi: 10.1002/mrm.25106
13. Muranaka H., Horiguchi T., Usui S. et al. Dependence of RF heating on SAR and implant position in a 1.5T MR system. Magnetic Resonance in Medical Sciences, 2007, vol. 6, no. 4, pp. 199–209. doi: 10.2463/mrms.6.199
14. Shellock F.G. Radiofrequency energy-induced heating during MR procedures: a review. Journal of Magnetic Resonance Imaging, 2000, vol. 12, no. 1, pp. 30–36.

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License