Emergency physicians face both continued emphasis on cost containment and the introduction of newer, often more expensive, imaging options. An evidence-based, cost-effectiveness analysis directs rational utilization of limited medical resources. Although charges or reimbursement may serve as proxies for cost, they often do not accurately reflect the resources consumed; see Table 2. Though not easily quantified, hidden imaging costs include ED staff utilization, opportunity costs, and risks associated with the procedure. Travel from the ED for imaging requires staff to deliver and collect the patient and may occupy a nurse for continuous monitoring. Longer image acquisition and radiologist interpretation times delay patient disposition. This translates into the cost of forgone opportunity to direct resources toward the next patient in need.