RESUMO
OBJECTIVE: The purpose of this study was to evaluate the effects and applicability of use of the American College of Radiology (ACR) Appropriateness Criteria by nonradiologist physicians in an MRI preauthorization center. MATERIALS AND METHODS: All MRI requests received at our preauthorization center during a 19-month period were included in the study. The study period was divided into preintervention and postintervention phases, indicating before and after introduction of the ACR criteria to the general practitioners staffing our center. ACR appropriateness values were classified into three groups: appropriate, indeterminate, and inappropriate. Requests for which a matching ACR value could not be assigned were labeled ACR-noncodable. Multiple parameters evaluated and compared for the two phases included rate of request receipt, total approval and denial rates, and approval and denial rates according to the ACR Appropriateness Criteria and by anatomic region to be evaluated. RESULTS: There was no significant change in rate of request receipt and total approval and denial rates. However, there was an increase in the rate of approval of appropriate requests (phase 1, 71/96 [74%]; phase 2, 74/76 [97%]; p < 0.001) and the rate of denial of inappropriate requests (phase 1, 0/12 [0%]; phase 2, 9/13 [69%]; p < 0.001). More than 40% of requests were marked "ACR-noncodable" because of a lack of a matching clinical condition or variant. CONCLUSION: Introduction of the ACR Appropriateness Criteria resulted in an increase in the rate of performance of appropriate MRI examinations and a decrease in the rate of performance of inappropriate MRI examinations. ACR Appropriateness Criteria were applicable to approximately 50% of MRI requests.