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A novel target-field method for magnetic resonance shim coils: III. Shielded zonal and tesseral coils


Forbes, LK and Crozier, S, A novel target-field method for magnetic resonance shim coils: III. Shielded zonal and tesseral coils, Journal of Physics D: Applied Physics, 36, (2) pp. 68-80. ISSN 0022-3727 (2003) [Refereed Article]

DOI: doi:10.1088/0022-3727/36/2/302


This paper continues the development of a new approach for the design of shim and gradient coils, used in magnetic resonance imaging (MRI) applications. A cylindrical primary coil of radius a and length 2L is placed inside a co-axial shield cylinder of radius b. An active shielding strategy is used to create a desired target field at an arbitrarily specified (cylindrical) location within the primary coil, and to annul the field at a certain radius outside the shield. The form of the interior target field may be chosen arbitrarily by the designer, although zonal and tesseral harmonics are typically used in MRI applications. The method presented here designs coil windings on both the primary and shielding cylinders, to produce fields that conform to the specified interior target field and the annulled field exterior to the shield. An additional feature of the method presented here is that the target field inside the primary coil is matched at two different radii, to improve overall accuracy. The method is illustrated by designing several shielded shim coils, for creating higher order tesseral fields located asymmetrically within the coil. The simpler case of pure zonal fields is discussed separately and applied to the design of some higher order shielded coils.

Item Details

Item Type:Refereed Article
Research Division:Physical Sciences
Research Group:Condensed matter physics
Research Field:Electronic and magnetic properties of condensed matter; superconductivity
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the mathematical sciences
UTAS Author:Forbes, LK (Professor Larry Forbes)
ID Code:25049
Year Published:2003
Web of Science® Times Cited:40
Deposited By:Mathematics
Deposited On:2003-08-01
Last Modified:2004-04-20

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