Evidence for Diagnostic Imaging Guidelines

In response to the widespread concern about the increasing use of diagnostic imaging and the concern that a significant portion of the diagnostic imaging being performed is not helpful in patient management and therefore not necessary [1], the ACR has developed and continues to refine the ACR Appropriateness Criteria [2] to assist referring physicians in ordering the most appropriate diagnostic imaging in given clinical situations. As with all clinical practice guidelines, referral guidelines for diagnostic imaging such as the ACR Appropriateness Criteria, should be evidencebased [3]. Guideline producers need to assess the grade of the evidence on which their guidelines are based, but they should also provide an assessment of the strengths of their recommendations, which should be linked to the quality of the evidence [3]. The Grading of Recommendations Assessment, Development and Evaluation (GRADE)Working Group’s methodology is becoming widely accepted as the most appropriate methodology for assessing the quality of evidence and linking it to the strength of a recommendation in clinical practice guidelines [4]. GRADE initially developed its methodology for guidelines for patientmanagement and rightly considered evidence about patient outcomes the most important type of evidence [5]. GRADE considers evidence about patient outcomes to be the most important type of