Variation in CTA evaluation of ED patients suspected of aortic dissection

Abstract

Purpose: This study was performed to investigate the variation in CTA imaging for AoD in an ED to determine if limiting the scanned region to the chest can effectively rule-out AoD without delaying care.

Methods: A retrospective chart review was performed for all patients belonging to a geographically isolated health maintenance organization who underwent CTA evaluation for possible acute AoD in the emergency department between 2016 and 2020. We evaluated for the regions included in the CTA, the presence of an acute AoD, and clinical outcomes. For those who were ruled-out of an AoD with a CTA limited to the chest, we investigated clinical follow-up up to 6 months after their initial presentation.

Results: Over the study period, there were 1143 CT scans ordered by ED physicians to evaluate for AoD in patients without a history of AoD. Only 23.0% of screening studies were of the chest only. There were 29 acute AoDs diagnosed (14 type A and 15 type B) making for a prevalence of 2.5%. Only one patient with an acute AoD detected on a chest-only CTA required farther imaging, which did not delay clinical care. No patients ruled-out for acute AoD with a chest-only CTA had a return ED visit or repeat CTA within 6 months diagnosing a missed AoD. There were no AoDs limited to the abdominal aorta that would have been missed on a chest-only study.

Conclusion: In patients in the ED with suspected new acute AoD, a CTA limited to the chest can effectively evaluate the condition without delaying care in this integrated healthcare system with 24/7 CT availability.

Keywords: Aortic dissection; CT; Emergency department; Radiation dose.