Can you remember the last time you worked a shift in the emergency department and ordered zero computed tomography (CT) scans? Can you even imagine a time in history when the number of CT scans to rule out pulmonary embolism ordered was compiled in a monthly total rather than a daily report? There was, indeed, a time when it was not so common to parade a CT about town in such innovations as mobile stroke units.

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With minimal barriers to use and the appeal of diagnostic certainty, CT use has spiraled out of control. Choosing Wisely implicates excessive use of advanced imaging as low-value care consumers should question. Despite ACEP publishing its own recommendations for avoiding low-value imaging and the known financial and physiologic harms of CT overuse, the literature remains replete with examples of inappropriate use. In even just the past few months, multiple publications have indicted a wide variety of imaging modalities:

Cervical Spine Imaging in Trauma

The ground-level fall is an extraordinarily common presenting mechanism of injury. Some days it seems nearly every single nursing home resident spends their day innovating new ways to evade their caregivers and find their way down to the floor.

These patients frequently arrive fully immobilized in full trauma regalia and undergo CT of the cervical spine for clearance. This single-center review of 760 ground-level fall presentations identified seven fractures—six stable and one unstable.¹ The authors further reviewed each chart individually and suggested only 50 percent of charts supplied sufficient documentation to support appropriateness of imaging according to National Emergency X-Radiography Utilization Study (NEXUS) Low-Risk Criteria or Canadian Cervical-Spine Rule. Conversely, at least 20 percent of charts supplied enough information to judge imaging as definitely inappropriate.

The authors estimate consistent use of validated decision instruments just for ground-level falls could reduce imaging-related costs $12–$31 million annually in the United States.

Pulmonary Embolism

The ACEP Clinical Policy Statement for the evaluation of pulmonary embolism (PE) is clear: In patients with a low pretest probability for suspected PE, the Pulmonary Embolism Rule-Out Criteria (PERC) can be used to exclude the diagnosis based on history and physical alone.² This statement is not an endorsement of PERC as a “zero miss” decision instrument but, rather, recognition of the harms relating to long-term anticoagulation and the generally low morbidity and mortality of PE in the setting of preserved normal physiology. The harms are likely understated as the acceptable miss rate used in PERC does not account for the high rates of false positives recognized in patients with low pretest probability for PE. In the interests of protecting patients and decreasing unnecessary CT use, the rate of CT for PE in PERC-negative patients should be nearly zero.