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High-resolution small field-of-view magnetic resonance image acquisition system using a small planar coil and a
1Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. k_miki@atre.t.u-tokyo.ac.jp.
Background:
Low-field open magnetic resonance imaging (MRI) is frequently used for performing image-guided neurosurgical procedures. Intraoperative magnetic resonance (MR) images are useful for tracking brain shifts and verifying residual tumors. However, it is difficult to precisely determine the boundary of the brain tumors and normal brain tissues because the MR image resolution is low, especially when using a low-field open MRI scanner. To overcome this problem, a high-resolution MR image acquisition system was developed and tested.
Methods:
An MR-compatible manipulator with pneumatic actuators containing an MR signal receiver with a small radiofrequency (RF) coil was developed. The manipulator had five degrees of freedom for position and orientation control of the RF coil. An 8-mm planar RF coil with resistance and inductance of 2.04 [Formula: see text] and 1.00 [Formula: see text] was attached to the MR signal receiver at the distal end of the probe. MR images of phantom test devices were acquired using the MR signal receiver and normal head coil for signal-to-noise ratio (SNR) testing.
Results:
The SNR of MR images acquired using the MR signal receiver was 8.0 times greater than that of MR images acquired using the normal head coil. The RF coil was moved by the manipulator, and local MR images of a phantom with a 2-mm grid were acquired using the MR signal receiver. A wide field-of-view MR image was generated from a montage of local MR images.
Conclusion:
A small field-of-view RF system with a pneumatic manipulator was integrated in a low-field MRI scanner to allow acquisition of both wide field-of-view and high-resolution MR images. This system is promising for image-guided neurosurgery as it may allow brain tumors to be observed more clearly and removed precisely.
Insights
A novel radiofrequency (RF) coil system significantly enhances magnetic resonance imaging (MRI) resolution for neurosurgery. This advancement improves visualization of brain tumors, aiding precise surgical removal.
Area of Science:
- Medical Imaging
- Neurosurgery
- Biomedical Engineering
Background:
- Low-field open MRI is crucial for image-guided neurosurgery, but suffers from low resolution, hindering precise tumor boundary identification.
- Current limitations in magnetic resonance (MR) image resolution impede accurate visualization of brain tumors and normal tissues.
Purpose of the Study:
- To develop and test a high-resolution MR image acquisition system to overcome the resolution limitations of low-field open MRI scanners.
- To improve the precision of image-guided neurosurgery by enhancing the clarity of tumor visualization.
Main Methods:
- An MR-compatible manipulator with a 5-degree-of-freedom pneumatic actuator controlled a small radiofrequency (RF) coil.
- An 8-mm planar RF coil was integrated with an MR signal receiver at the probe's distal end.
- MR images were acquired using the developed system and a standard head coil for comparison.
Main Results:
- The MR signal receiver achieved an 8.0-fold increase in signal-to-noise ratio (SNR) compared to the standard head coil.
- High-resolution local MR images of a 2-mm grid phantom were acquired by maneuvering the RF coil.
- A wide field-of-view MR image was successfully generated by mosaicking local images.
Conclusions:
- Integration of a small field-of-view RF system with a pneumatic manipulator in low-field MRI enables acquisition of both wide field-of-view and high-resolution images.
- This system shows promise for image-guided neurosurgery, offering clearer observation and more precise removal of brain tumors.
