Development of a Magnetoinductive Lens for Magnetic Resonance Imaging

作者：Wu, Jie; Li, Bing Nan^*

来源：IEEE INSTRUMENTATION & MEASUREMENT MAGAZINE, 2017, 20(6): 56-60.

DOI：10.1109/MIM.2017.8121953

• REFRACTION
• MRI

Magnetic resonance imaging (MRI) is an advanced medical modality aiming to excite in vivo atoms and perceive their responses ex vivo with adiofrequency (RF) coils [1]. The quality of images is subject to the abundance of target atoms, the power of exciting coils, and the sensitivity of receiving coils, etc. In practice, the abundance of target atoms is application specific, and the power of RF excitation is limited by the specific absorption rate (SAR). It is thus a long-standing topic in the field of MRI study to improve efficiency and resolution [2], [3]. In this article, we present a magnetoinductive lens (MIL) with negative permeability by using metamaterials to enhance the signal-To-noise ratio (SNR) of MRI surface coils. The metamaterial capacitor-loaded metallic rings (CLRs) are designed and fabricated on a thin slab to guide the propagation of near-field electromagnetic waves. This metamaterial MIL is able to focus the B1 field at the Larmor frequency nearby 297.2 MHz for 7.0 T MRI. The results of MRI scanning with and without MIL show that the surface coil is enhanced about three times in terms of SNR. Its potentials in spatial resolution and penetration depth are preliminarily demonstrated as well.

• 出版日期2017-12
• 单位合肥工业大学