CAD program delivers near-real-time guidance in OR

A computer-aided diagnostics program is delivering interactive 3D to the operating room at Jefferson Hospital for Neuroscience in Philadelphia, visualizing brain tumors and the location of electrodes during surgery designed to stop seizures.

MediCAD software integrates diffusion tensor imaging and functional fMRI and displays them on PCs in the operating room. MediCAD provides neurosurgeons a near-real-time interactive digital map of patients' brains, slicing, zooming, and reformatting data.

"Incorporating DTI and fMRI in presurgical planning holds great promise for advancing our ability to remove a targeted lesion while minimizing postoperative neurological deficits by avoiding damage to functioning white matter fiber tracts and cortical gray matter," said Song Lai, Ph.D., an associate professor of radiology and director of MRI physics at Thomas Jefferson University.

The software defines the relationship between tumors and surrounding tissue, according to Jefferson Hospital neurosurgeon David Andrews, indicating whether tumors are infiltrating or displacing white matter tracts. This information has relevance to the surgical team in the OR and helps guide physicians calculating patient prognoses.

"Specific to brain tumor patients, it is important to be able to distinguish between infiltrative and expansive tumors, since the (cancer) growth pattern allows a complete resection without neurologic compromise," Andrews said. "We have also learned that the expansive tumors lead to a far better prognosis than the infiltrative tumors."

In regard to surgery on patients with epilepsy, the interactive 3D system provides a better understanding of the relationship between areas where seizures begin and neighboring brain structures. This supports safe and effective surgery to stop seizures, according to Dr. Christopher Skidmore, a neurologist in the Jefferson Comprehensive Epilepsy Center.

As part of the patient workup prior to surgery, brain scans are done the day before in order to obtain the most up-to-date imaging data. The short time between scanning and surgery requires a tool that can quickly provide detailed integrated information, Andrews said. The MediCAD system does so by tapping into images archived in the hospital's PACS, reconstructing them, and routing them to the OR.

"With these questions in mind, a multimodal visualization system was developed that allows for performing these query tasks in real-time and produces quantitative results," Lai said.

The software is fast, requires no preprocessing beyond standard fMRI analysis, and can be built into existing medical visualization systems, he said.