Usefulness of triphasic CT aortic angiography in acute and surveillance: Our experience in the assessment of acute aortic dissection and endoleak

Abstract

Introduction: Computed tomography angiography (CTA) has been widely used in the diagnostic evaluation of many aortic diseases, but no standardized techniques actually exist for aortic CTA. The aim of this study was to describe the usefulness of triphasic CTA in aortic assessment in both non-traumatic emergency and surveillance conditions.

Methods: We performed non ECG-gated CTA examinations with a 64-slice CT scanner using a triphasic protocol consisting of an unenhanced acquisition, and two (early and delayed) contrastographic phases with a delay of 25-30 s and 100-120 s respectively after the injection of contrast medium. Were retrospectively selected adult patients with imaging findings of acute aortic dissection (AAD) or endoleak (EL) from November 2012 to November 2014.

Results: AAD was detected in 36 (67%) patients: 23 type A-AADs, and 13 type B-AADs. The presence of EL was observed in 18 (33%) patients: 1 type Ia, 5 types IIa, 2 types IIb, 1 type IIIa and 9 types IIIb.

Discussion: Triphasic CTA is useful to provide correct and prompt diagnosis of AAD in emergency, allowing the evaluation of type and atypical forms of AAD, and the identification of possible branch-vessel involvement and complications. During surveillance, triphasic CTA assures accurate and complete assessment of all known and unknown ELs and it is essential for first follow-up examination.

Conclusion: Triphasic CTA represents a reliable imaging tool for aortic assessment in both non-traumatic emergency and surveillance after endovascular aneurysm repair. Modified protocol could be employed in selected patients and tailored in their known disease.

Keywords: Acute aortic dissection; Computed tomography angiography (CTA); EVAR; Endoleaks; Triphasic CTA.