Clinical value of computed tomography scanning and magnetic resonance imaging: studies in the United Kingdom.

Abstract

Acad Radio11996;3:S49-$50 9 1996, Association of University Radiologists B ecause of the relatively high cost of computed tomography (CT) scanning and magnetic resonance (MR) imaging, and the prevailing economic climate at the time of their introduction, the clinical value of these two techniques has been extensively investigated. Such analysis was especially intense in the United Kingdom because many of the original CT scanning and MR imaging systems were donated to hospitals by charitable organizations. Hospital authorities then had to decide whether and how to afford to continue running such units when charitable funding had ceased. Accordingly, few other imaging (or therapeutic) techniques have been subjected to such scrutiny. In the late 1970s and early 1980s, the science of assessing the value of imaging techniques was still developing. An early randomized study of the use of CT scanning for an abdominal mass [1] showed that CT scanning could shorten the average hospital stay, displace other tests, and reduce overall costs per patient. Proof of the displacement of other tests was demonstrated by the decline in requests for lymphography [2]. In addition, it was noted that many more requests were made for the noninvasive test (CT) scanning than had ever been made for the invasive one (lymphography). Interventional CT scanning procedures were shown to produce even greater benefit. Cost-benefit studies [3] indicated considerable savings to the medical community with appropriate use of CT scanning, even if the total cost for a radiology department escalated. MR imaging was only slowly introduced into the United Kingdom. Many of the original systems were in university depamnents, and as a result, a considerable amount of outcomes research was done to persuade the United Kingdom's National Health Service that MR imaging was of clinical value. Accordingly, interest was keen in the effect of MR imaging on the clinician's diagnosis, the clinician's intended management plan, and the patient's quality of life. One of the more impressive early studies was the Glasgow randomized trial that compared blR imaging with c r scanning for possible lesions in the posterior fossa [4]. In this study, 1,020 patients were randomized either to MR imaging or CT scanning subgroups, b!ore MR studies were subsequently requested in patients who were