CT Scanners in the ED: Impact on Workflow Efficiency


The benefits of having a CT scanner located in a hospital’s emergency room have long been recognized for the ability to expedite treatment of injured or critically ill patients by its proximity and accessibility. A formal study conducted by researchers at the University of Ottawa in Ontario to quantify this assumption was published in the March issue of the Journal of the American College of Radiology. Time durations of workflow starting with order entry through preliminary interpretation of two acute, tertiary-care teaching hospital facilities of the Ottawa Hospital were evaluated.

Both hospitals share the same rotating emergency medicine and radiology staff. Institutional protocols for the emergency departments, the radiology departments, and the labs are identical, and both hospitals use the same RIS and PACS. The same number of radiologists and radiology residents are physically present in the emergency departments at each site. One hospital has a CT scanner in the emergency department and the other does not. Its CT scanners are located in the radiology department, approximately 985 feet away.

With respect to utilization, the CT scanner located in the emergency department is utilized almost exclusively for emergency patients, but may also be used for inpatients and ambulatory patients. At the other hospital, all types of patients are scheduled for the two CT scanners, although emergency patients take priority.

The retrospective study, led by Dr. Ania Z. Kielar of Ottawa Hospital’s Department of radiology, evaluated 1,696 patients admitted to the two emergency departments who had acute thoracic and/or abdomino-pelvic CT scans performed at one of the two hospitals during a 90 day time period in 2012. The 776 patients imaged with the emergency department CT scanner and the 920 imaged at the other hospital were stratified based on indication (hyperacute, acute and subacute conditions). Exams were also stratified by two daytime work shifts and one night shift and by the training level of the radiologist/resident making a preliminary/final interpretation. The percentage of exams requiring contrast was comparable at both hospitals, as were the patient throughput capabilities of the CT scanners.

For all shifts, workflow was faster at the hospital with the emergency department CT scanner, specifically by 16 minutes for the morning shift, 15 minutes for the afternoon shift, and 19 minutes for the night shift for a nontrauma scan. Based on the study findings, the authors suggested that the benefits of an emergency department CT scanner may have more impact in community centers that have an adequate number of experienced radiology staff rather than a mix of radiologists and residents. They believe their findings will be useful for hospitals trying to improve efficiency of imaging patients admitted to the emergency department.

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  1. Dang, W, Kielar AZ, Fu, AYN et al. Does distance matter? Effect of having a dedicated CT scanner in the mergency department on completion of CT imaging and final patient disposition times. JACR 2015; 12 (3): 277-283.
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CT Scanners in the ED: Impact on Workflow Efficiency.  Appl Radiol. 

March 19, 2015

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