Head CT Scans May Be Overused in Emergency Departments

Marcia Frellick

February 02, 2015

Most patients presenting to the emergency department (ED) with syncope or dizziness may not benefit from a computed tomography (CT) scan of the head unless they are older than 60 years, have a focal neurologic deficit, or have a history of recent head trauma, researchers have found.

Myles Mitsunaga, MD, resident at John A. Burns School of Medicine, University of Hawaii, Honolulu, and Hyo-Chun Yoon, MD, from the Department of Diagnostic Imaging, Kaiser Foundation Hospital, Honolulu, studied the clinical factors that potentially predict acutely abnormal head CT findings and hospital admission.

They studied electronic medical records of all patients who came to a health maintenance organization emergency department between July 1, 2012, and December 31, 2012, who underwent head CT for a primary complaint of dizziness, syncope (defined as a transient loss of consciousness and postural tone), or near-syncope.

Of the 253 patients who presented with dizziness, 7.1% had head CT scans with acutely abnormal findings; 18.6% were admitted. Of the 236 patients who presented with syncope or near-syncope, 6.4% had head CT scans with acutely abnormal findings; 39.8% were admitted. These results were published in the January issue of the American Journal of Roentgenology.

The authors do not recommend head CT scans in patients with loss of consciousness unless physicians suspect the loss of consciousness is not syncope.

"Most patients with mild symptoms of dizziness or syncope do not require a head CT," Dr Mitsunaga said in a news release. "If a careful history and physical examination do not find persistent neurologic signs, then a follow-up clinic visit the next day may be all that is necessary."

However, three clinical factors were found to be significantly linked with acutely abnormal head CT findings: a focal neurologic deficit (P = .003), age greater than 60 years (P = .011), and acute head trauma (P = .026).

Their results add to others that have found ED physicians commonly use head CT scans to evaluate patients with syncope, even though there is little evidence of benefit.

"Head CT ideally should be used as a diagnostic test rather than a screening one because of its expense and unnecessary radiation exposure to the patient," the authors write.

The current diagnostic yield for the scan is too low, they say, which indicates that head CT is currently being used more as a screening test rather than to confirm or exclude a diagnosis.

"Although a defined acceptable diagnostic yield for head CT in the evaluation of dizziness or syncope has yet to be established, we suggest that, at a minimum, the diagnostic yield should be 10% or greater," the authors write.

The authors have disclosed no relevant financial relationships.

Am J Roentgenol. 2015;204:24-28. Abstract


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