An annual review by a multidisciplinary expert panel of the American College of Radiology Appropriateness Criteria has determined ventilation and perfusion scans to diagnose pulmonary embolism remain largely accurate and useful in certain settings. Lower-extremity ultrasound can substitute by demonstrating deep vein thrombosis; however, if negative, further studies to exclude PE are indicated. In all cases, correlation with the clinical status, particularly with risk factors, improves not only the accuracy of diagnostic imaging, but also overall utilization. Other diagnostic tests have limited roles.
In instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment, they concluded.