Computed tomography: cost and efficacy implications.

Because CT is unique, it has been accepted by physicians with unrestrained enthusiasm. However, the capital investment and cost of maintenance are high, and there has been no orderly program of dispersion despite the profound interest of the regulatory agencies in cost containment. Although the diagnostic accuracy of CT in both the head and body is high, its information gain over other competing imaging methods, particularly those in the abdomen (ultrasound, nuclear medicine), has not been fully documented. In evaluating the cost effectiveness of CT, long-term outcome, while the most important criterion, requires carefully controlled studies over many years. Short-term value may be measured by assessing the degree to which CT furnishes new diagnostic information, its accuracy, its effect on the morbidity and mortality of diagnostic and theraupeutic procedures, its impact on treatment planning, and changes in cost and saving incident to its use. Prospective studies must relate the contribution of CT to that of competing methods and document the impact of additional diagnostic information.