## Abstract Techniques are described for the design of shielded gradient coils for superconducting MRI systems. These design methods are suited for constructing the most efficient gradient coil that meets a specified homogeneity requirement. Tradeoffs in coil design of efficiency with coil size and
Shielded gradient coils on hyperbolic surfaces of revolution
β Scribed by Joseph W. Carlson; Mark S. Roos
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 949 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0740-3194
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
A formalism for the calculation of fields generated by current distributions on hyperbolic surfaces of revolution is presented and used to generate designs for shielded gradient coils. One application is the development of small, insertable coils suitable for head imaging while allowing clearance for shoulders. This technique demonstrates that efficient designs that offer substantial advantages over conventional cylindrical designs are possible.
π SIMILAR VOLUMES
## Abstract Alternate expressions for the current density on the shielding surface of a gradient coil are derived for cylindrical, planar, and hyperbolic gradient coils. For the planar and hyperbolic geometries, these expressions allow more rapid highβprecision calculations of current densities tha
## Abstract A shielded gradient system and radio frequency probes for a 4.7βT/30βcm horizontal bore magnet are described. The systems were designed principally to obtain images and localized spectra from rat brains. The gradients can operate in either a shielded or non shielded mode. The rf probe,
## Abstract Because radiation loss associated with a radiofrequency (RF) coil increases as roughly the fourth power of the frequency, this loss mechanism may become important in highβfield studies above 2.0 T. In this study, the contribution of radiation losses at 4.0 T were determined in a rectang
## Abstract A surface gradient coil designed to obtain localized magnetic resonance spectroscopy of the heart __in vivo__ is described. Images and ^31^P spectra from phantoms and both pig and dog hearts __in vivo__ are shown. The coil was used in conjunction with a rf surface coil to obtain ^31^P s
## Abstract Although in the design of transmit RF coils, B~1~ homogeneity is crucial for good image quality, discussion of electric field (Eβfield) distribution in the literature has been mostly limited to specific absorption rate (SAR) and patient loading (dielectric) effects. In this work, we rep