Robotic Device for Acquisition ofWide and High Resolution MRI Image Using a Small RF Coil

摘要

This paper proposed a prototype of wide and high resolution MRI acquisition system for MRI-guided surgery. Currently, MRI-guided neurosurgical procedures are performed in an operating room with open MRI, and intraoperativeMR images are provided with real time rich biological information. However, the low resolution of the MR images is still problem and it is difficult to determine precise boundary of the tumor and normal tissue especially when using a low tesla open-type MRI. To solve this problem, a method to acquire wider and higher resolution MR images using a small RF coil is proposed. The outer diameter of the RF coil is 8 mm and its inductance and resistance of the RF coil were 1.0 μH and 2.0 Ω. To receive MRI signals with high efficiency, 1 DOF bending mechanism, which is mounted on the distal tip of the MRI signal receiver, was developed to control the orientation angle of the RF coil. Bending the distal tip of MRI signal receiver, the transmission efficiency of MRI signals is kept high and SNR of MR images was kept high. The SNR of MR images using MRI signal receiver was 11.3 and the voxel size of MR images is 0.5 × 0.5 × 1.0mm~3. We successfully obtained clear MR images of okra and the voxel size of MR images is 0.5×0.5×1.0mm~3. These results show that the MRI signal receiver is useful to acquire wide and high-resolution MR images.