GE explores infrared imaging with Beth Israel

GE Healthcare is working with Beth Israel Deaconess Medical Center to develop imaging systems that use near-infrared (NIR) fluorescent light to guide surgeons and interventionalists.

GE Global Research is spearheading corporate development, while Beth Israel's Frangioni Laboratory is working on the academic side. In early October, the two announced receipt of a $6.5 million grant from the Cancer Imaging Program of the National Cancer Institute (NCI) to support a five-year collaboration on NIR imaging. The goal is to visualize tissues deep in the body, thereby enabling less invasive forms of surgery.

Biologic tissues, hemoglobin, water, and fat are least absorbent in the near-infrared spectrum, roughly 650 to 900 nanometers. This property allows NIR photons to penetrate deeply. But "deep" is a relative term.

Though studies conducted so far have visualized tissues only about 10 mm below the surface, the applications being developed by GE and the Frangioni Laboratory don't really need any greater penetration, as the technology will be applied invasively. Better visualization with NIR may give surgeons and interventionalists a better grasp of a cancer's location and its border with healthy tissues, raising the potential for reduced patient morbidity and longer survival.

"Right now we have established a proof-of-concept large subject animal imaging system that is suitable for open surgical procedures," said Steve Lomnes, program leader for biomedical optics, GE Global Research. "To make this system more compatible with additional clinical applications, we are using the (NCI) funds to extend its capability to endoscopy and laparoscopy."

GE and the Frangioni Laboratory have been working together on NIR imaging for the past few years, using early successes to win greater and longer term funding from the U.S. government. These funds, along with seed money from GE, have supported the development of prototype intraoperative imaging systems based on NIR light. Recent advances include zoom and autofocus features. Several systems have been sited in U.S. research labs.

A system dedicated to small animal research and a second designed for large animals are operating at the Frangioni Laboratory. A third is being tested at Brigham and Women's Hospital, where its research applications are limited to animal studies. A fourth is in use at the Purdue School of Veterinary Medicine.

"Part of our strategy is to work with partners to try to expand clinical indications," Lomnes said.

The prototypes all use fluorescent contrast agents, which are being developed in concert with the hardware platforms. GE Global Research is leveraging its expertise in medical imaging system design and signal processing to increase the sensitivity of the system for open surgical applications and make customized minimally invasive systems.

The initial design of a prototype imaging system for open surgeries could be completed by the end of 2006, according to GE. Engineers hope to have a fully functional and completed surgical imaging system ready for clinical use in five years.

Early applications may include image-guided sentinel lymph node mapping, image-guided cancer resection with real-time assessment of surgical margins, and intraoperative detection of metastases in the surgical field.