Whole-body CT screening is now spreading across the country like a wildfire on a hot, windy day. In big and medium-sized cities in the United States, it is difficult to avoid the advertisements promoting CT screening in the print media, on radio and TV, and even over the Internet. Testimonials abound by celebrities who proclaim the life-saving value of unenhanced CT. Typically, they proffer the notion that individuals who seem to be entirely well and avail themselves of this examination wisely take advantage of the opportunity to find that they are either free of disease or are lucky to have discovered that they have something they can take care of before it is "too late."
The emerging industry of total-body screening may become a global phenomenon, at least in affluent countries, because CT centers similar to those in the United States are now opening in Europe (Pinto F, personal communication). In many locales, the proponents of the technique can sound persuasive as they present arguments that are enticing to prospective patients. Yet, like any novel technology that has advantages and applications that appear obvious, CT screening also possesses attendant uncertainties and risks that need to be emphasized. Moreover, it engenders perhaps unanticipated but nonetheless real and difficult issues for the specialty of radiology that tend to be overlooked in the hoopla.
CT screening can be divided into four categories: calcium scoring of coronary arteries; cross-sectional imaging of the chest for the prime purpose of observing small carcinomas; colonography for the detection of large-bowel polyps; and abdominal scanning for the recognition of any abnormality, be it degenerative, metabolic, vascular, or neoplastic. Chest and abdominal CT screening are often performed together as one examination, but I will confine my comments to CT studies performed on asymptomatic patients for the evaluation of disorders in organs and tissues below the diaphragm.