Eddy current effects on a clinical 7T-68 cm bore scanner.
BACKGROUND
Eddy currents induced by switching of magnetic field gradients can lead to distortions in short echo-time spectroscopy or diffusion weighted imaging. In small bore magnets, such as human head-only systems, minimization of eddy current effects is more demanding because of the proximity of the gradient coil to conducting structures.


METHODS
In the present study, the eddy current behavior achievable on a recently installed 7 tesla-68 cm bore head-only magnet was characterized.


RESULTS
Residual effects after compensation were shown to be on the same order of magnitude as those measured on two whole body systems (3 and 4.7 T), while using two to three fold increased gradient slewrates.
Kickler
Nils
N
Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. NilsKickler@googlemail.com
van der Zwaag
Wietske
W
Mekle
Ralf
R
Kober
Tobias
T
Marques
Jose P
JP
Krueger
Gunnar
G
Gruetter
Rolf
R
D017097:Electric Impedance; D004574:Electromagnetic Fields; D006257:Head / Q000473:pathology / Q000502:physiology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008280:Magnetics; D019047:Phantoms, Imaging; D051598:Whole Body Imaging