The use of cross-sectional diagnostic imaging in a major Canadian health care centre

To assess current patterns of use of cross-sectional imaging at 5 large Canadian teaching hospitals and a cancer centre, in order to better predict future use.

We prospectively reviewed all requisitions for diagnostic imaging during a 2-week period in January 2002. Each requisition was assessed by means of a form on which the attending radiologist answered 6 questions about the appropriateness and usefulness of the requested examination.

A total of 2374 examinations were audited: 1167 ultrasonography, 925 computed tomography and 282 magnetic resonance imaging examinations. Forms with scores of 3 out of 7 or more for the appropriateness and relevance of the imaging request (n = 2229) were not examined further. After review of the remaining complete forms, 59 (2.5%) were found to contain at least 1 score that was less than 3 out of 7, which was considered to be a failing grade.

There is a low incidence of inappropriate use of diagnostic imaging. Practical ways to reduce unnecessary use would include close attention to the wasteful practice of test duplication and to the need for patient education to help minimize unnecessary testing.