Virtual endoscopy: a promising new technology.

Growing evidence shows that early detection of cancer can substantially reduce mortality, necessitating screening programs that encourage patient compliance. Radiology is already established as a screening tool, as in mammography for breast cancer and ultrasonography for congenital anomalies. Advanced processing of helical computed tomographic data sets permits three-dimensional and virtual endoscopic models. Such models are noninvasive and require minimal patient preparation, making them ideal for screening. Virtual endoscopy has been used to evaluate the colon, bronchi, stomach, blood vessels, bladder, kidney, larynx, and paranasal sinuses. The most promising role for virtual endoscopy is in screening patients for colorectal cancer. The technique has also been used to evaluate the tracheobronchial tree for bronchogenic carcinoma. Three-dimensional and virtual endoscopy can screen, diagnose, evaluate and assist determination of surgical approach, and provide surveillance of certain malignancies.