Stanley der to classify them as likely or unlikely to have the cancer that is the object of the screen [12]. In terms of outcome, the objective is to reduce morbidity and mortality from that cancer among the persons screened, achieved at a reasonable cost [12].

The concept of a critical point in a disease needs to be emphasized. The critical point is the time when treatment is more effective before that point than after. Screening must find the disease before that time. For example, if the critical point in the disease is just before the development of metastases, then the screening test may be of value. If the critical point occurs long before the screening test is capable of detecting the pathologic morphology, then there is clearly no point in subjecting a person to the screening test. In a recent edition of Applied Radiology [13], one of the editors, Robert Harris, cited the opinion of Paul Chang, the director of informatics and PACS (picture archiving and communication system) at the University of Pittsburgh, on the entire-body CT scan performed on paying “customers” to screen for potential disease. He called them “yuppie scans,” seemingly designed for the self-absorbed, immortality-seeking types prevalent in that generation. In the December 2000 issue of Diagnostic Imaging, an article by Michael Brant-Zawadzki [14], entitled “Screening on Demand: Portent of a Revolution in Medicine,” has an introductory subtitle that asks the following question:“When they are willing to pay themselves, can patients be denied information about their own bodies?” My question is, precisely what sort of information will be conveyed to these “patients”? Presumably, the screens will be done on asymptomatic individuals who would theoretically be in the preclini-