Powerful MRI Helps in Nerve Surgery

Using a high-power magnetic resonance imaging device, U.S. doctors were able to predict outcomes in removing disabling nerve tumors.

A team of Mayo Clinic surgeons said Friday that the 3-Tesla imaging device provides detail to assess treatment in patients with rare sciatic notch dumbbell-shaped tumors.

In the past, if surgeons couldn’t tell prior to surgery where the exact location of the large tumor was in relation to the sciatic nerve, it meant they couldn’t predict in which cases surgery could be performed safely, said Robert Spinner, the lead neurosurgeon on the Rochester, Minn.-based Mayo Clinic team. Its report is published in the current issue of the Journal of Neurosurgery.

In the report, Mayo physicians describe a case study of five patients. Four had neurofibromatosis, a condition with a predisposition to nerve-related tumors. The tumors were benign but resulted in neurologic dysfunction and disabling pain. Using the 3-Tesla device, the doctors were able to distinguish that, in three cases, surgery would eliminate the tumor without damaging the nerve. Follow-up surgery was successful in these cases.

The more powerful device — most commercially used imagers employ 1-Tesla magnets — is useful in the sciatic tumors because the shape and location make them difficult to discern with less intense imaging. The rarity of the tumors also makes study difficult.

Surgeons need an accurate picture of how and whether they can remove a tumor while protecting a nerve. Otherwise, patients may be exposed to the risks of surgery without achieving surgical benefits if the tumor is inoperable because complete removal would damage a nerve. Our experience demonstrates the advantages of predictive imaging at the outset, said Spinner.