Is CT utilization in the emergency department appropriate?

Tuesday, November 29 | 9:30 a.m.-10:30 a.m. | T3-SSNPM02-4 | Room E352

Is utilization of CT -- as well as MRI and ultrasound -- appropriate in the emergency department? It could be better, Stanford researchers say.

Even though evidence-based guidelines for appropriate advanced imaging use are widely available, the rate of inappropriate imaging referrals is still high; 60% of inappropriate imaging tests are returning normal results, presenter Dr. Stephan Altmayer, PhD, and colleagues found.

The group reviewed 330 each of CT, ultrasound, and MRI exams from patients who presented in the emergency department between January and March 2018. The parameters of the analysis were a prevalence of inappropriate orders of 30% with a margin of error of 5%. Two radiologists used the American College of Radiology's (ACR) guidelines to come to consensus about whether an exam was appropriate or not; the final imaging report was compared with the exam's initial order using the following categories: "normal," "compatible with initial diagnosis," "alternative diagnosis," or "inconclusive."

Altmayer and colleagues found the following rates of inappropriate orders: CT, 29.1%; MRI, 33.3%; and ultrasound, 59.4%. The study showed that inappropriately ordered tests were more likely to show no abnormalities compared with appropriate referrals:

• CT: 62.5% (inappropriate referral) versus 34.2% (appropriate referral)
• MRI: 61.8% (inappropriate referral) versus 38.7% (appropriate referral)
• Ultrasound: 65.8% (inappropriate referral) versus 38.8% (appropriate referral)

It also showed that the final reports of appropriate referrals were significantly more likely to be compatible with the initial diagnosis compared with inappropriate tests.

• CT: 46.6% (appropriate) versus 14.6% (inappropriate)
• MRI: 56.3% (appropriate) versus 21.8% (inappropriate)
• Ultrasound: 45.5% (appropriate) versus 14.3% (inappropriate)

"More than 60% of the inappropriate tests were normal for all modalities, while around 50% of appropriate orders had findings compatible with the initial clinical suspicion," the group concluded. "This highlights the impact that correct exam selection has on finding confirmative or actionable results on imaging."

Attend this Tuesday scientific presentation to get all of the details.