+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Radiofrequency heating effects around resonant lengths of wire in MRI

, : Radiofrequency heating effects around resonant lengths of wire in MRI. Physics in Medicine and Biology 47(16): 2973-2985

Several recent reports agree that the potentially dangerous heating around extended wires or coaxial cables inside the bodycoil of a magnetic resonance imager is related to resonant effects. No quantitative description of this idea has been given so far. We analyse a simplified situation, where a straight metallic wire is completely surrounded by a large volume of homogeneous dielectric with a small conductivity. If it has the correct length, the wire acts as a receiving-and-retransmission antenna, changing the axial symmetry of the incoming electric field into a radially outgoing electric field near the wire ends. The latter field points into the conducting surroundings, causing dissipation. Some simple experiments on geometries related to this theoretical model provide support to the main conclusions. These suggest that under actual imaging conditions resonant effects might be avoided by choosing a wire length of about 2 m. However, more experimental work remains to be done to validate this suggestion.


PMID: 12222860

DOI: 10.1088/0031-9155/47/16/312

Other references

Mooney, A.C.; Robertson, H.M.; Wanner, K.W., 2009: Neonate silkworm (Bombyx mori) larvae are attracted to mulberry (Morus alba) leaves with conspecific feeding damage. The silkworm Bombyx mori is a molecular genetic model for the Lepidoptera. Its odorant receptor genes have been described, and preliminary studies suggest that several are expressed specifically in the larval caterpillar stage. This study was unde...

Chung, E.K., 1973: Cardiac arrhythmias. Rationale of drug therapy. Singapore Medical Journal 14(3): 325-333

Cockerell, T.D.A., 1901: A new Cecidomyiid on Gutierrezia. Canadian Entomologist, XXXIII 23

Sohn, H-Joo.; Kim, J-Hoon.; Choi, K-Seuk.; Nah, J-Ju.; Joo, Y-Seok.; Jean, Y-Hwa.; Ahn, S-Whan.; Kim, O-Kyung.; Kim, D-Yong.; Balachandran, A., 2002: A case of chronic wasting disease in an elk imported to Korea from Canada. A seven-year-old male elk (Cervus elaphus nelsoni) was euthanized and necropsied after having a 3-week history of body weight loss, emaciation, excessive salivation, teeth grinding, fever, anorexia, and respiratory distress. The elk was imported i...

Huang, S.; Zhang, J.; Tao, Z.; Lei, L.; Yu, Y.; Huang, L., 2015: Enzymatic conversion from pyridoxal to pyridoxine caused by microorganisms within tobacco phyllosphere. Vitamin B6 (VB6) comprises six interconvertible pyridine compounds (vitamers), among which pyridoxal 5'-phosphate (PLP) is a coenzyme involved in a high diversity of biochemical reactions. In plants, PLP is de novo synthesized, and pyridoxine...

Akers, T.G.; Hashem, N.; Mahdy, M.S., 1960: Studies on paralytic poliomyelitis in Cairo, U.A.R., 1957-1958. American Journal of Tropical Medicine and Hygiene 9: 343-349

Sackton, T.B.; Lazzaro, B.P.; Clark, A.G., 2010: Genotype and gene expression associations with immune function in Drosophila. It is now well established that natural populations of Drosophila melanogaster harbor substantial genetic variation associated with physiological measures of immune function. In no case, however, have intermediate measures of immune function, such...

Kishko, I.G., 1976: Molecular biological bases for the tumorigenic action of viruses. Mikrobiolohichnyi Zhurnal 38(3): 374-382

Razzaque, M.S.; Soegiarto, D.W.; Chang, D.; Long, F.; Lanske, B., 2005: Conditional deletion of Indian hedgehog from collagen type 2alpha1-expressing cells results in abnormal endochondral bone formation. Indian hedgehog (Ihh) is actively involved in endochondral bone formation. Although expression of Ihh is mostly restricted to pre-hypertrophic chondrocytes, the role of chondrocyte-derived Ihh in endochondral bone formation is not completely under...

Szabo, Y., 1991: Landscaping with wildflowers. News and views 76(6): 12