An optimized target-field method for MRI transverse biplanar gradient coil design
| Autor: | Youyi Fu, Kefu Huang, Rui Zhang, Jing Fang, Jing Xu, Yangjing Li, Jue Zhang |
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| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | Measurement Science and Technology. 22:125505 |
| ISSN: | 1361-6501 0957-0233 |
| DOI: | 10.1088/0957-0233/22/12/125505 |
| Popis: | Gradient coils are essential components of magnetic resonance imaging (MRI) systems. In this paper, we present an optimized target-field method for designing a transverse biplanar gradient coil with high linearity, low inductance and small resistance, which can well satisfy the requirements of permanent-magnet MRI systems. In this new method, the current density is expressed by trigonometric basis functions with unknown coefficients in polar coordinates. Following the standard procedures, we construct an objective function with respect to the total square errors of the magnetic field at all target-field points with the penalty items associated with the stored magnetic energy and the dissipated power. By adjusting the two penalty factors and minimizing the objective function, the appropriate coefficients of the current density are determined. Applying the stream function method to the current density, the specific winding patterns on the planes can be obtained. A novel biplanar gradient coil has been designed using this method to operate in a permanent-magnet MRI system. In order to verify the validity of the proposed approach, the gradient magnetic field generated by the resulted current density has been calculated via the Biot–Savart law. The results have demonstrated the effectiveness and advantage of this proposed method. |
| Databáze: | OpenAIRE |
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