A Micro Saddle Coil with Switchable Sensitivity for Local High-Resolution Imaging of Luminal Tissue

作者：Dohi Tetsuji^*; Murashige Kousuke

来源：Micromachines, 2016, 7(4): 67.

DOI：10.3390/mi7040067

• micro coil
• magnetic resonance imaging (MRI)
• saddle coil
• switchable sensitivity

This paper reports on a micro saddle coil for local high-resolution magnetic resonance imaging (MRI) fabricated by embedding a flexible coil pattern into a polydimethyilsiloxane (PDMS) tube. We can change the sensitivity of the micro coil by deforming the shape of the coil from a saddle-shaped mode to a planar-shaped mode. The inductance, the resistance, and the Q-factor of the coil in the saddle-shaped mode were 2.45 mu H, 3.31 Omega, and 39.9, respectively. Those of the planar-shaped mode were 3.07 mu H, 3.92 Omega, and 42.9, respectively. In MRI acquired in saddle-shaped mode, a large visible area existed around the coil. Although the sensitive area was considerably reduced in the planar-shaped mode, clear MRI images were obtained. The signal-to-noise ratios (SNR) of the saddle-shaped and planar-shaped modes were 194.9 and 505.9, respectively, at voxel size of 2.0 x 2.0 x 2.0 mm(3) and 11.7 and 37.4, respectively, at voxel size of 0.5 x 0.5 x 1.0 mm(3). The sensitivity of the saddle-shaped and the planar-shaped modes were about 3 times and 10 times higher, respectively, than those of the medical head coil at both voxel sizes. Thus, the micro saddle coil enabled large-area imaging and highly sensitive imaging by switching the shape of the coil.

• 出版日期2016-4