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Literature DB >> 23248293

NMR imaging of cell phone radiation absorption in brain tissue.

Abstract

A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance frequency shift of hydrogen protons in brain tissue. This proposed application of NMR thermometry offers sufficient spatial and temporal resolution to characterize the hot spots from absorbed cell phone radiation in aqueous media and biological tissues. Specific absorption rate measurements averaged over 1 mg and 10 s in the brain tissue cover the total absorption volume. Reference measurements with fiber optic temperature sensors confirm the accuracy of the NMR thermometry.

Entities: Chemical Species

Mesh：

Substances：
Gels
Protons

Year: 2012 PMID： 23248293 PMCID： PMC3538231 DOI： 10.1073/pnas.1205598109

Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205

33 in total

Review 1. Historical review of RF exposure standards and the International Committee on Electromagnetic Safety (ICES).

Authors: John M Osepchuk; Ronald C Petersen
Journal: Bioelectromagnetics Date: 2003 Impact factor: 2.010

2. FLASH imaging: rapid NMR imaging using low flip-angle pulses. 1986.

Authors: A Haase; J Frahm; D Matthaei; W Hänicke; K-D Merboldt
Journal: J Magn Reson Date: 2011-12 Impact factor: 2.229

3. Brain tumour risk in relation to mobile telephone use: results of the INTERPHONE international case-control study.

Authors:
Journal: Int J Epidemiol Date: 2010-05-17 Impact factor: 7.196

4. Re-analysis of risk for glioma in relation to mobile telephone use: comparison with the results of the Interphone international case-control study.

Authors: Lennart Hardell; Michael Carlberg; Kjell Hansson Mild
Journal: Int J Epidemiol Date: 2010-12-17 Impact factor: 7.196

Review 5. MR thermometry.

Authors: Viola Rieke; Kim Butts Pauly
Journal: J Magn Reson Imaging Date: 2008-02 Impact factor: 4.813

6. Ex vivo tissue-type independence in proton-resonance frequency shift MR thermometry.

Authors: R D Peters; R S Hinks; R M Henkelman
Journal: Magn Reson Med Date: 1998-09 Impact factor: 4.668

7. Age-dependent tissue-specific exposure of cell phone users.

Authors: Andreas Christ; Marie-Christine Gosselin; Maria Christopoulou; Sven Kühn; Niels Kuster
Journal: Phys Med Biol Date: 2010-03-05 Impact factor: 3.609

8. Effects of cell phone radiofrequency signal exposure on brain glucose metabolism.

Authors: Nora D Volkow; Dardo Tomasi; Gene-Jack Wang; Paul Vaska; Joanna S Fowler; Frank Telang; Dave Alexoff; Jean Logan; Christopher Wong
Journal: JAMA Date: 2011-02-23 Impact factor: 56.272

9. Some present problems and a proposed experimental phantom for SAR compliance testing of cellular telephones at 835 and 1900 MHz.

Authors: Om P Gandhi; Gang Kang
Journal: Phys Med Biol Date: 2002-05-07 Impact factor: 3.609

NMR imaging of cell phone radiation absorption in brain tissue.

Review 1. Historical review of RF exposure standards and the International Committee on Electromagnetic Safety (ICES).

2. FLASH imaging: rapid NMR imaging using low flip-angle pulses. 1986.

3. Brain tumour risk in relation to mobile telephone use: results of the INTERPHONE international case-control study.

4. Re-analysis of risk for glioma in relation to mobile telephone use: comparison with the results of the Interphone international case-control study.

Review 5. MR thermometry.

6. Ex vivo tissue-type independence in proton-resonance frequency shift MR thermometry.

7. Age-dependent tissue-specific exposure of cell phone users.

8. Effects of cell phone radiofrequency signal exposure on brain glucose metabolism.

9. Some present problems and a proposed experimental phantom for SAR compliance testing of cellular telephones at 835 and 1900 MHz.

10. Real-time measurement of RFR energy distribution in the Macaca mulatta head.

1. Heat equation inversion framework for average SAR calculation from magnetic resonance thermal imaging.

Review 2. Effect of Cell Phone Radiations on Orofacial Structures: A Systematic Review.

3. A method for safety testing of radiofrequency/microwave-emitting devices using MRI.

4. Does the Brain Detect 3G Mobile Phone Radiation Peaks? An Explorative In-Depth Analysis of an Experimental Study.

5. Collective responses in electrical activities of neurons under field coupling.

6. Effects of short and long term electromagnetic fields exposure on the human hippocampus.

7. Mobile Phone Radiation Deflects Brain Energy Homeostasis and Prompts Human Food Ingestion.