Emergency CT misdiagnosis in acute aortic syndrome.

Objectives: This cross-sectional study assessed the accuracy of emergency CT reports at presentation in acute aortic syndrome (AAS).

Methods: Retrospective identification of cases of AAS presenting within a large health board with three acute hospitals receiving adult patients between January 2013 and December 2016. CT studies and reports at presentation were reviewed for discrepancies related to diagnosis, complications and classification by two cardiovascular radiologists. The specialist interest of the original reporters, clinically suspected diagnosis at referral for CT and technical adequacy of the scans were also assessed. False-positive diagnoses were identified and evaluated separately.

Results: Among 88 consecutive confirmed cases of AAS at least one discrepancy was identified in 31% ( = 27), including failure to identify or misinterpretation of the AAS itself in 15% ( = 13), haemorrhage in 13% ( = 11), branch involvement in 9% ( = 8), and misclassification in 3% ( = 3). All discrepancies occurred among the 80% ( = 70) of cases reported by radiologists without specialist cardiovascular interest. 26% ( = 23/88) of AAS cases were not clinically suspected at referral for CT and although this was associated with suboptimal protocols, only 51% of CT scans among suspected cases were technically adequate. Seven false-positive diagnoses were identified, three of which related to motion artefact.

Conclusion: Significant discrepancies are common in the emergency CT assessment of positive cases AAS and this study highlights important pitfalls in CT technique and interpretation. The absence of discrepancies among radiologists with specialist cardiovascular interest suggests both suspected and confirmed cases warrant urgent specialist review.

Advances In Knowledge: CT angiography is central to the diagnosis of AAS; however, significant radiology discrepancies are common among non-specialists. This study highlights important pitfalls in both CT technique as well as interpretation and supports routine specialist cardiovascular imaging input in the emergency assessment of AAS.