CHICAGO--By creating a virtual reality environment, physicians in the not-too-distant future will be able to move through, around, and into a patient's airways to search for tumors, enlarged lymph nodes, and abnormal masses in the walls of the bronchi and surrounding tissue on a computer screen, David J. Vining, MD, predicted at the annual scientific meeting of the Radiological Society of North America.
"What we're doing right now is relatively crude, but what we'll be doing in 5 years will be very sophisticated," said Dr. Vining, assistant professor of radiology, Bowman Gray School of Medicine, Winston-Salem, NC. [A report on Dr. Vining's research on virtual colonoscopy appeared in the July, 1994, issue of Oncology News International (ONI), page 29.]
By the turn of the century, virtual reality technology probably will be advanced enough to be used routinely to obtain three-dimensional (3D) views of the airways that reveal anatomic structures which normally remain hidden during bronchoscopy, such as the lymph nodes and blood vessels. It will provide a clear road map physicians can follow to guide the placement of biopsy needles in suspicious lymph nodes during standard bronchoscopy, he said.
The technology also will be able to identify patients who should not be subjected to bronchoscopy. "Sometimes, bronchoscopy is unsuccessful because there are blockages in the bronchi that restrict access with an endoscope. Other times, there is a tumor that is situated so it can't be seen with an endoscope. Virtual bronchoscopy will be very good at predicting these things in advance, thus sparing the patient the discomfort and expense of an unsuccessful exam," Dr. Vining said.
25 Simulations to Date
To date, virtual reality simulations of the interior of the airways have been created on more than 25 patients, to provide physicians with a way of evaluating thin-section spiral computed tomographic (CT) images from the perspective of the bronchoscopist. Special software converts the CT images into 3D graphic elements that can be displayed on a computer console and manipulated by means of a computer mouse. "With this technology, physicians can view exquisitely detailed reproductions of their patient's anatomy as 3D, movable models on a video screen. The physicians can then search for a tumor or other abnormality by 'navigating' through the body, using a computer mouse to guide the direction of travel," Dr. Vining explained.
In a number of ways, virtual reality examination of the airways has proved to be more medically illuminating than conventional bronchoscopy, he added. The technology accurately predicted bronchial involvement by mediastinal tumors, identified areas of bronchial stenosis and bronchiectasis, and discovered several unsuspected conditions, such as multiple aberrant bronchi.