Title :
Designing MR Shim Arrays With Irregular Coil Geometry: Theoretical Considerations
Author :
While, Peter T. ; Korvink, J.G.
Author_Institution :
Dept. of Microsyst. Eng. (IMTEK), Univ. of Freiburg, Freiburg, Germany
Abstract :
In magnetic resonance imaging and spectroscopy, a highly uniform magnetic field is desired for minimizing image distortions and line broadening, respectively. Typically, shim coils are employed to provide correcting fields for inhomogeneities brought about by magnetic interactions with the sample under study. Flexible field modeling is possible using an array of regularly shaped conducting loops that are independently electrically driven. In this paper, a design method is presented for generating coil winding patterns for shim arrays with irregular geometry elements. These designs are compared theoretically to the use of circular loop arrays and are shown to provide considerable improvements in field accuracy and efficiency for generating low-order correcting fields.
Keywords :
arrays; biomedical MRI; biomedical equipment; coils; design; geometry; magnetic fields; magnetic resonance spectroscopy; shims; MR shim array design; circular loop arrays; coil winding pattern generation; correcting fields; electrically driven conducting loop; field accuracy; field efficiency; flexible field modeling; image distortion minimization; inhomogeneities; irregular coil geometry; line broadening minimization; low-order correcting field generation; magnetic interactions; magnetic resonance imaging; magnetic resonance spectroscopy; regularly shaped conducting loop array; uniform magnetic field; Coils; Geometry; Magnetic resonance imaging; Nonhomogeneous media; Optimization; Superconducting magnets; Windings; Active shimming; coil design; shim array; spherical harmonic (SH) fields;
Journal_Title :
Biomedical Engineering, IEEE Transactions on
DOI :
10.1109/TBME.2013.2293842