by Michael Johns
, Project Manager | July 07, 2006
This article is from the University of California, Irvine Medical Center website.
Operating on the Brain
Until recently, neurosurgeons had to rely on images of the brain taken just before surgery to guide them through complex procedures.
The shifting brain.
Called intraoperative MRI, the system utilizes electromagnetic waves to produce highly detailed pictures of the brain as the operation unfolds. "Because the brain is composed of soft tissue, it constantly shifts during surgery," says Dr. Mark Linskey, chairman of the UCI Department of Neurological Surgery and co-director of the multidisciplinary Neuro-Oncology Program at UCI Medical Center's Chao Family Comprehensive Cancer Center. "As a result, the brain is never in precisely the same position before an operation as during it." Now, instead of relying on scans taken pre- and post-surgically, doctors can see the brain in three-dimensional detail during all stages of an operation. This allows them to monitor subtle shifts in brain tissue as they occur, resulting in increased surgical precision.
Before, during and after.
Here's how it works: Scans taken before the first incision pinpoint the location of the tumor in exacting detail. This helps doctors determine the best surgical pathway to minimize contact with healthy tissue. During surgery, the intraoperative MRI system alerts surgeons to the slightest movement of the brain within the skull. This can arise from the surgical manipulation necessary to access a tumor, or the shifting of tissue due to other causes. Based on this information, doctors can make minor adjustments in their approach to the tumor, remaining meticulously on target. The MRI machine also optically tracks the doctor's surgical instruments, showing their precise location in relation to the patient's anatomy. This information allows neurosurgeons to avoid delicate structures within the brain.
"Another major benefit of the intraoperative MRI system is that it gives doctors an incredibly detailed look at brain tumors," says Linskey. "We can see exactly where the tumor ends and normal tissue begins." Having access to this information allows neurosurgeons to verify that the entire growth has been removed without increasing risk to nearby healthy brain tissue. "In the past, surgeons had to rely on scans taken after surgery to confirm that the entire malignancy had been removed," says Linskey. "If part of the tumor remained, another operation was needed." The intraoperative MRI system helps avoid this situation, resulting in safer surgery--and fewer follow-up operations for patients.