Electrodynamics and radiofrequency antenna concepts for human magnetic resonance at 23.5 T (1 GHz) and beyond

Content Provider	Semantic Scholar
Author	Winter, Lukas Niendorf, Thoralf
Copyright Year	2016
Abstract	ObjectiveThis work investigates electrodynamic constraints, explores RF antenna concepts and examines the transmission fields (B1+) and RF power deposition of dipole antenna arrays for 1H magnetic resonance of the human brain at 1 GHz (23.5 T).Materials and methodsElectromagnetic field (EMF) simulations are performed in phantoms with average tissue simulants for dipole antennae using discrete frequencies [300 MHz (7.0 T) to 3 GHz (70.0 T)]. To advance to a human setup EMF simulations are conducted in anatomical human voxel models of the human head using a 20-element dipole array operating at 1 GHz.ResultsOur results demonstrate that transmission fields suitable for 1H MR of the human brain can be achieved at 1 GHz. An increase in transmit channel density around the human head helps to enhance B1+ in the center of the brain. The calculated relative increase in specific absorption rate at 23.5 versus 7.0 T was below 1.4 (in-phase phase setting) and 2.7 (circular polarized phase setting) for the dipole antennae array.ConclusionThe benefits of multi-channel dipole antennae at higher frequencies render MR at 23.5 T feasible from an electrodynamic standpoint. This very preliminary finding opens the door on further explorations that might be catalyzed into a 20-T class human MR system.
Starting Page	641
Ending Page	656
Page Count	16
File Format	PDF HTM / HTML
DOI	10.1007/s10334-016-0559-y
PubMed reference number	27097905
Journal	Medline
Volume Number	29
Alternate Webpage(s)	http://edoc.mdc-berlin.de/15684/1/15684oa.pdf
Alternate Webpage(s)	https://doi.org/10.1007/s10334-016-0559-y
Journal	Magnetic Resonance Materials in Physics, Biology and Medicine
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article