MR imaging during brain surgery improves tumor removal

A specially adapted magnetic resonance imaging (MRI) scanner can help physicians remove brain tumors and all of the residual cancer during one surgical procedure, according to a study published in the October issue of the journal Radiology. Using intraoperative MR-guidance, surgical strategy was changed in one out of four cases.

“Imaging during surgery provides intraoperative quality control. It presents valuable information during the procedure that allows the surgeon an opportunity to adjust the strategy,” said lead author Christopher Nimsky, M.D., an associate professor at the University Erlangen-Nürnberg in Germany. Prior to intraoperative imaging, small parts of the tumor could be inadvertently missed. This tumor residue usually required repeated surgery, surveillance or further treatment.

The researchers reported their first clinical experience with intraoperative high-field MRI of 200 patients. They evaluated the extent of tumor removal depicted by intraoperative imaging and how surgical strategy was altered. The investigators found that imaging quality was indistinguishable between the pre- and intraoperative scans. In 27.5 percent of cases, intraoperative MRI impacted surgical strategy, often depicting additional tissue that needed to be removed.

MR is the imaging modality of choice for preoperative diagnosis of brain tumors and epilepsy. In the mid 1990s the advancement of open MR systems extended its practicality to the operating room. The researchers have now applied high-field scanning capabilities to intraoperative MR. High-field MR produces better image quality with reduced scan time. However, high-field MR is still an expensive imaging modality and will be for at least the next few years.

Dr. Nimsky envisions that in the future, flat MR scanners might be placed underneath operating tables to further optimize the intraoperative application of MR imaging technology. He said that the optimal solution is a nearly invisible imaging system that provides real-time feedback to the neurosurgeon without disturbing the surgical workflow.