Abstract No. 412 Biphasic contrast CT for endoleak identification

Abstract

Endoleaks are the Achilles heel of aortic intervention as these can lead to sac expansion and potential rupture if untreated. The mainstay of follow-up is CT angiography (CTA). We set out to compare the image quality of conventional CTA with biphasic injection CT in endoleak surveillance post aortic intervention. 42 consecutive patients who underwent aortic stenting and had surveillance CTA were subsequently followed up with a biphasic CT with a single acquisition at 70 s. Only those without further intervention in between studies were included. Images were analyzed for arterial, venous and parenchymal attenuation. Two separate semi-quantitative 5-point scoring systems were used to assess the arterial and parenchymal image quality. All studies were double reported and the presence of endoleaks compared. Although the mean arterial enhancement was higher in the CTA group, overall arterial image quality was comparable (P = 0.1097, n = 40). There were no non-diagnostic studies in either group. Solid organ enhancement was significantly better in the biphasic CT group (P < 0.0001). There were two non-diagnostic parenchymal studies in the biphasic CT group compared with seven in the CTA group. Endoleak identification was comparable in the two groups (correlation coefficient of 0.849). One type II endoleak was only seen on the biphasic study, while another type II was only seen on CTA. Comparable arterial image quality and endoleak detection can be achieved using a biphasic intravenous contrast injection CT protocol while allowing for solid abdominal organ assessment.