Experimental evaluation of nonlinearities of small-sized insertable gradient coils.
A phase imaging technique is proposed to map out and quantify gradient nonlinearities of small-sized insertable gradient coils, assuming the whole-body system gradients are highly linear in the domain of interest. The theory is developed and simple equations are derived to allow quantification. It is applied to a 4-loop 18-cm diameter cylindrical gradient coil of optimal design. Experimental gradient nonlinearity maps are obtained for different fields of view. Gradient non-linearities are quantified locally and in regions of interest, showing close agreement with model data.
Morvan
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INSERM U.484 and Department of Biophysics, Centre Jean-Perrin, Clermont-Fd, France. morvan@inserm484.u-clermont1.fr
Richard
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B
Fredy
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D
D000465:Algorithms; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods / Q000706:statistics & numerical data; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D017711:Nonlinear Dynamics; D019047:Phantoms, Imaging / Q000706:statistics & numerical data