Neuroradiologists telepresent during MR-guided neurosurgery

Remotely viewed MR images are helping neuroradiologists guide surgeons during brain surgery.

The brain changes shape as structures shift during neurosurgery, making navigation less accurate as the procedure progresses. Obtaining MR scans during surgery enables surgeons to judge the results of their efforts. When removing a tumor, for instance, the neurosurgeon can see how much tumor has been removed and the locations of remaining tumor tissue. More than 200 of these interventional MR procedures have been performed at the University of California, Los Angeles.

According to Dr. Gregory J. Rubino, director of interventional MR at UCLA, neurosurgery performed with MR guidance offers superior definition of brain anatomy and the relationships between critical normal structures and the surgical lesion. This permits accurate lesion localization with smaller, more focused craniotomies, which limit surgical risk to normal brain. It also enables assessment of the extent of tumor resection and diagnosis and treatment of intraoperative complications prior to wound closure, thereby decreasing the chance of permanent neurological injury.

But neurosurgeons, who are not necessarily expert at interpreting MR scans in all cases, sometimes require collaboration with neuroradiologists. When this is necessary the surgical procedure stops, the radiologist is paged and everyone - surgical team and anesthetized patient - wait for the neuroradiologist to arrive.

"Waiting drives the cost of surgery up because they charge by the hour," said Keyvan Farahani, Ph.D., an assistant professor of radiological sciences at UCLA. "Plus, the radiologist has to interrupt his or her work to come to the OR. Proper utilization of MRI in neurosurgical guidance requires real-time consultation with a neuroradiologist on demand throughout a procedure that may take as long as eight hours."

Farahani's solution is a telecollaboration scheme that allows neurosurgeons to consult with neuroradiologists during all stages of MR-guided procedures.

The prototype system modifies PACS workstations by implementing "application sharing" to allow telecollaboration. With this capability radiologists anywhere on the network can view images and telecollaborate with the surgeon in the OR, Farahani said. The radiologist can remotely navigate through the images, annotate them, make notes, prescribe imaging techniques, and interact with the surgeons, all in real-time.

"Teleconferencing has been used in medicine before, but this is crucial application because here you have a patient on the table and you're using high-tech medicine to treat them," Farahani said. "But you don't want the surgeon overwhelmed with hundreds of MR images when only a few are necessary. We want the surgeon to be able to concentrate on the surgery. This is why we need neuroradiologist presence."