Interventional MR scanner assumes role as neurosurgery tool

November 8, 2000

The FDA in early October cleared an MR scanner for use in neurosurgery. The PoleStar N-10, Odin Medical Technologies' 0.12-tesla permanent magnet system, rises from under the operating table to sandwich the patient's head and provide real-time

The FDA in early October cleared an MR scanner for use in neurosurgery. The PoleStar N-10, Odin Medical Technologies' 0.12-tesla permanent magnet system, rises from under the operating table to sandwich the patient's head and provide real-time guidance.

"This is not a diagnostic imaging tool, but it is sufficient to provide the neurosurgeon with the key answer, and that is whether to continue to cut or not," said Hillel Bachrach, president of Odin, the Israeli firm that developed the system.

The intraoperative scanner, which lists for $960,000, can be installed in a standard operating room suite outfitted with the proper radio-frequency shielding and equipped with MR-compatible tools, Bachrach said. Preparing the site for MR operations bumps the cost higher, with the final tally dependent on the particulars of the individual site. Shielding is minimized, however, by a compact magnetic field with a 5-gauss line that extends just 5 feet from the magnet's isocenter.

The final cost may be a bargain, considering the end result: access to real-time data indicating whether the tumor has been completely removed. Competing real-time systems, the Hitachi Airis II and GE Signa SP/i open mid-field systems, cost $900,000 to $2 million, respectively. Less costly alternatives, such as neuronavigational tools that process MR data obtained prior to surgery, cannot account for the shifting of brain tissue that occurs during an operation.

The gap between the two magnets in the PolerStar is wide enough to fit the patient's head in any position, while providing sufficient access for the surgeon. Real-time images guide the procedure, allowing continuous evaluation of a tumor resection prior to closure of the surgical wound.

Obtaining real-time data with Odin's PoleStar N-10 promises to yield anatomical precision. Among the possible patient benefits from more accurate surgery are quicker recuperation time, shorter hospital stays, fewer complications, and less potential for recurrence, according to the company.

Odin was founded in September 1995. R&D is concentrated in Yokneam, Israel, and the company opened a subsidiary this year to support sales and marketing operations in the U.S. Four units have been installed at sites around the world: one each in Zurich and Israel, and two in the U.S., at the Cleveland Clinic and the University of Medicine and Dentistry of New Jersey. By year's end, three additional sites are scheduled to open in the U.S., Bachrach said.

The PoleStar was officially unveiled at the American Association of Neurological Surgeons convention in April and was most recently exhibited at the Congress of Neurological Surgeons in September. It will not, however, be on display at the upcoming RSNA meeting, as company executives have chosen to focus sales efforts entirely on neurosurgeons.

"It is not an imager; it is a navigation system‹a neurosurgery tool," Bachrach said. "So there is no need for a radiologist to be involved."

Bachrach plans to sell the system in the U.S. using its own sales force as well as sales agents under the direction of Odin.