dB/dt Evaluation in MRI Sites: Is ICNIRP Threshold Limit (for Workers) Exceeded?

International Journal of Environmental Research and Public Health

FrancescaMaria Salmeri¹  Giuseppe Acri¹  Carlo Sansotta¹  Barbara Testagrossa¹  Elisa Ruello¹  Lucia Denaro¹  Giuseppe Vermiglio²  Girolamo Garreffa³  Carmelo Anfuso⁴  Patrizia Inferrera⁵ 

[1] Department of BIOMORF, University of Messina, Via Consolare Valeria, 98168 Messina, Italy;Department of P.A.S.S.I., University of Messina, Consolare Valeria, 98168 Messina, Italy;IEMEST (PA), Fondazione Potito (CB), FISMECO (RM), Via G. Donati, 00159 Roma, Italy;IRCCS Centro Neurolesi “Bonino-Pulejo”, Via Palermo, C.da Casazza, 98123 Messina, Italy;School on Medical Physic, University of Messina, Via Consolare Valeria, 98168 Messina, Italy;

关键词: static magnetic field;    time-varying magnetic field;    MRI safety;    MRI workers exposure;   

DOI  :  10.3390/ijerph15071298

来源: DOAJ

【 摘 要 】

The Directive 2013/35/EU establishes standards for workers exposed to static and time varying magnetic fields. These limits are based on ICNIRP guidelines expressed in terms of the electric field induced in the body. The complexity of this measurement led to theoretical models being developed. In this study, the experimental evaluation included varying magnetic field exposures for two classes of MRI workers. The measurements are conducted on four different MRI Systems including one 0.35 T, two 1.5 T, and one 3.0 T. Pocket magnetic dosimeters were used and it was carried out during routine conditions, emergency conditions, and cold-head maintenance/substitution. The acquired data has been processed and the corresponding dB/dt curves have been computed as the first time derivative of the dataset. The weighted peak approach was also implemented for the compliance assessment with regulatory limits. The dB/dt peak values have been compared with the reference level (RL) proposed by ICNIRP. The results show that the RL always exceeds during measurements on the 3.0 T scanner and sometimes on 1.5 T. In light of the foregoing, the diffusion of ultra-high field MRI scanners involves the introduction of behavioral rules that could be more useful than a numerical action level.

【 授权许可】

Unknown