Colorectal cancer is the second leading cause of cancer-related death in America. Colonoscopies can help detect pre-cancerous conditions, but on a scale of one to ten of the things most feared by the public, the colonoscopy is right up there The reluctance of the general public to get screened is a real problem. Just ask Katie Couric.
The answer has just arrived.
Dr. Arie Kaufman, at the State University of New York (SUNY) Stony Brook Computer Science Department, with support and funding from ONR, has developed the Virtual Colonoscopy. It is an accurate, fast, non-invasive, patient-comfortable procedure for screening of colon polyps, the precursor of cancer. (In contrast, conventional colonoscopy is invasive with a risk of puncturing the colon and requires that the patient be sedated.)
ONR is supporting Kaufman's research on volumetric modeling and rendering (voxelbased, rather than surface-based computer graphics algorithms) . Kaufman uses these algorithms to render the virtual colon and visualize it interactively in real time. A 40-second single-breath-hold computed tomography (CT) scan of the patient's abdomen is taken. Volume visualization is then used to virtually navigate within an automatically segmented and reconstructed 3D model of the colon. The visualization software, running on a PC, allows physicians to interactively navigate through the virtual colon and includes customized tools to conduct "virtual biopsies" to inspect suspicious regions. Clinical studies demonstrated the effectiveness of the Virtual Colonoscopy in imaging and detecting polyps as small as 3 mm in diameter. The current procedure is being extended to interactive 3D virtual endoscopy for visualizing the interior of other organs, such as the heart, arteries, lungs, and stomach.
"In addition to the medical application discussed here, Kaufman's volume graphics algorithms have been used to visualize scientific and battlefield data. This is a good example of basic research being applied to both military and civilian applications," says Dr. Lawrence Rosenblum, ONR Program Officer for Visualization and Graphics.
The technology has been licensed to Viatronix Inc. (Stony Brook, NY), which has installed over two-dozen Virtual Colonoscopy V3D-ColonTM systems in the US, including National Naval Medical Center - Bethesda, Walter Reed Army Medical Center, and Naval Hospital - San Diego. These machines have already scanned over 1000 patients.
The set of figures below demonstrate the steps of the Virtual Colonoscopy procedure. Movies showing the navigation through the colon where actual polyps are identified from real data can be viewed at http://www.cs.sunysb.edu/~vislab/animations/colonoscopy/