Virtual bronchoscopy is a process by which a medical professional may obtain information about a patient's airways and the surrounding structures before using a bronchoscope on a patient. Using multiple overlays of views from computer tomography (CT) scans, a three-dimensional (3D) rendering of the bronchial airways and the lungs can show any lesions, tumors, abnormally narrow passageways, or any foreign bodies that may have been aspirated. A bronchoscopist, assisted by these 3D images, can guide instruments directly to the source of breathing problems to apply treatments or to biopsy tissues. Additionally, if a balloon is needed to expand a pathway or a stent needs to be placed, the precise measurements in diameter and length can be discovered before the procedure.
The virtual bronchoscopy procedure is noninvasive and, for that reason, is often used for young children, elderly patients, and those whose health conditions are unstable or cannot tolerate invasive procedures. By examining the views virtually, doctors can detect masses or lesions from inflammation or cancer. The software that is used for the virtual bronchoscopy allows a medical professional to "travel" through the airways virtually, and determine whether or not any pockets or tumors are obstructing blood vessels or the aorta. It is also possible to see whether lymph nodes outside the bronchi or within hilar regions of the lung, in the center, near the heart, might possibly be affected.
Simple bronchoscopy procedures, guided by a prior virtual bronchoscopy, have been used since the 1990s in very young children. As simple chest X-rays often miss over 30 percent of foreign bodies, virtual bronchoscopy can often show exactly where a foreign body is located. A foreign body's outline, size, and structure can be precisely viewed; this allows careful planning for removal, which can shorten the time needed for sedation and treatment. A simple x-ray might miss an aspirated grain of rice, for example, but a virtual bronchoscopy can detect that finely.
More complex uses of virtual bronchoscopy, such as guiding bronchoscopists while doing biopsies of lymph nodes, are still in clinical trials. These nodes may be just outside the bronchial passageways, or in the hilar regions in the upper lungs. During a normal bronchoscopy, it is not possible to view or accurately locate lymph nodes outside the bronchial passageways. Using virtual bronchoscopy images overlaying actual bronchoscopy images in real-time, however, allows a doctor to view the entire outline of a lymph node for accurate needle biopsy through the walls of a bronchial passage.