title: Temperature elevation in the fetus from electromagnetic exposure during magnetic resonance imaging.
abstract: This study computationally assessed the temperature elevations due to electromagnetic wave energy deposition during magnetic resonance imaging in non-pregnant and pregnant woman models. We used a thermal model with thermoregulatory response of the human body for our calculations. We also considered the effect of blood temperature variation on body core temperature. In a thermal equilibrium state, the temperature elevations in the intrinsic tissues of the woman and fetal tissues were 0.85 and 0.61 degrees C, respectively, at a whole-body averaged specific absorption rate of 2.0 W kg(-1), which is the restriction value of the International Electrotechnical Commission for the normal operating mode. As predicted, these values are below the temperature elevation of 1.5 degrees C that is expected to be teratogenic. However, these values exceeded the recommended temperature elevation limit of 0.5 degrees C by the International Commission on Non-Ionizing Radiation Protection. We also assessed the irradiation time required for a temperature elevation of 0.5 degrees C at the aforementioned specific absorption rate. As a result, the calculated irradiation time was 40 min.
authors.affiliation: Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. kikuchi@graduate.chiba-u.jp
authors.forename: Satoru
authors.initials: S
authors.lastname: Kikuchi
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Saito
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takahashi
authors.forename: Koichi
authors.initials: K
authors.lastname: Ito
mesh_terms: D001831:Body Temperature / Q000528:radiation effects; D001833:Body Temperature Regulation / Q000528:radiation effects; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005333:Fetus / Q000502:physiology / Q000528:radiation effects*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000009:adverse effects*; D008953:Models, Anatomic; D008954:Models, Biological; D011247:Pregnancy; D011846:Radio Waves / Q000009:adverse effects; D013546:Sweating / Q000528:radiation effects; D013696:Temperature