Philips' filet irons kinks out of virtual colonoscopy

Philips Medical Systems will serve up a CT filet at the RSNA meeting designed to catch colon cancer. The volumetric reconstruction of the colon, reconstructed from a high-resolution CT data set, takes out the reclusive turns and niches that can hide abnormalities indicating or presaging the development of colon cancer.

The Philips package will be highlighted in Chicago at a time when CT virtual colonoscopy appears on the verge of a breakthrough. Interest in the technique has grown steadily over the past decade. Clinical studies have indicated its value in detecting the early signs of this cancer, as patients who should be screened for colon cancer remain reluctant to use conventional means. The terrain of the colon has complicated matters, however. Fly-throughs and computer-aided diagnostics have done much to help, but not as much as physicians would like.

Philips addresses both accuracy and workflow. The software filets the mucosal colon wall, unfolding and spreading it wide. Virtual dissection splits the colon along its centerline, revealing the interior as a flat surface.

Its use can cut interpretation times from between 30 and 40 minutes to less than 10, according to Jason Plante, director of Philips' CT product portfolio.

Clinical experience with the package has documented these time savings. Further documentation is expected in the near future from sites using the package in the American College of Radiology Imaging Network National CT Colonography Trial, he said.

"We have built our product around the idea of driving toward the fastest time to diagnosis," he said. "We've come up with a unique view that unfolds the colon flat on the screen and in landscape mode to interrogate the entire colon very quickly."

Workflow issues have been one of the biggest stumbling blocks to the adoption of virtual colonoscopy. Searching the tiny, out-of-the-way spaces typically found in a CT reconstructed colon takes too long, said Plante, who compares the process to sitting in a car, looking in side and rearview mirrors.

"There are plenty of blind spots," he said. "The same is true of many virtual colonoscopy packages."

Philips' virtual colonoscopy package removes these blind spots, he said. Its perspective filet view unfolds the colon, then splits it down the center so the interpreter can see the 360 degrees interior as though it were spread flat. A computer-assisted reader colorizes suspicious lesions in the filet view. The lesion and surrounding tissue are magnified in a separate onscreen window. An accompanying window shows the position of the tissue being examined on a 2D map of the colon, and a third window shows 2D CT slices of the anomaly.

Workflow can be improved further by running the software on the company's Brilliance Workspace Portal, a thin client server that turns PCs and laptops into workstations. The portal provides access anywhere on the network.

"Our vision is that radiologists would have easy access to do the interpretations and be able to refer the case quickly to the gastroenterologist," Plante said. "If you see a polyp and the patient is prepped, you want to quickly get him or her over for colonoscopy to get the polyp removed."