Remotely operated MR-guided neurosurgical device in MR-operating room

A robust near real-time MRI based surgical guidance and navigation scheme has been developed, validated and used. The key concept of the method is to use intra-operative MRI to facilitate the trajectory alignment process of a biopsy needle in neurobiopsy. Since the trajectory corresponding to the biopsy needle pivoted at an entry point on patient skull has two degrees of freedom, the orientation of the needle can be tracked using a 2D imaging plane placed perpendicular to the desired trajectory. Using a near real-time visual feedback during the adjustment of an alignment guidance device, the required trajectory alignment was translated into a simple in-plane targeting task on computer monitor. The orientation adjustment was achieved remotely via a set of MR-compatible strings, which were connected to a joystick. The concept of MR-guided targeting was successfully validated on a phantom set-up. This MR based guidance technique has practically allowed neurosurgeons to accomplish the required needle alignment to an arbitrary trajectory remotely in a straight forward procedure on any conventional MR scanner. Before needle insertion, the trajectory can be validated. Two successful biopsy cases using the new methodology and device have shown that the remotely operated device under MR-guidance is both effective and accurate for neurosurgery.