Quantitative analysis of dynamic computed tomography angiography for the detection of endoleaks after abdominal aorta aneurysm endovascular repair: A feasibility study

• Authors: Georg Apfaltrer, Medical University of South Carolina; Francesco Lavra, Medical University of South Carolina; U. Joseph Schoepf, Medical University of South Carolina; Marco Scarabello, Medical University of South Carolina; Ricardo Yamada, Medical University of South Carolina; Marly van Assen, Medical University of South Carolina; Akos Varga-Szemes, Medical University of South Carolina; Brian E. Jacobs, Medical University of South Carolina; Maximilian J. Bauer, Medical University of South Carolina; William T. Greenberg, Medical University of South Carolina; Marcelo Guimaraes, Medical University of South Carolina; Luca Saba, Azienda Ospedaliero Universitaria; Carlo N. De Cecco, Emory University
• Journal Title: PLOS ONE
• Volume: Volume 16, Number 1
• Publisher: PUBLIC LIBRARY SCIENCE | 2021-01-07, Pages e0245134-e0245134
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1371/journal.pone.0245134
• Subjects: Health Sciences, Medicine and Surgery; Health Sciences, Radiology
• Keywords: Science & Technology; Multidisciplinary Sciences; Science & Technology - Other Topics; CT ANGIOGRAPHY; BLOOD-FLOW; CLASSIFICATION

Abstract

Objectives To assess the feasibility of quantitative analysis of dynamic computed tomography angiography (dCTA) for the detection of endoleaks in patients who underwent endovascular repair of abdominal aortic aneurysms (EVAR). Material and methods Twenty patients scheduled for contrast-enhanced CT angiography (CTA) of the abdominal aorta post-EVAR were prospectively enrolled. All patients received a standard triphasic CTA protocol, followed by an additional dCTA. The dCTA acquisition enabled reconstruction of color-coded maps depicting blood perfusion and a dCTA dataset of the aneurysm sac. Observers assessed the dCTA and dynamic CT perfusion (dCTP) images for the detection of endoleaks, establishing diagnostic confidence based on a modified 5-point Likert scale. An index was calculated for the ratio between the endoleak and aneurysm sac using blood flow for dCTP and Hounsfield units (HU) for dCTA. The Wilcoxon test compared the endoleak index and the diagnostic confidence of the observers. Results In total, 19 patients (18 males, median age 74 years [70.5-75.7]) were included for analysis. Nine endoleaks were detected in 7 patients using triphasic CTA as the reference standard. There was complete agreement for endoleak detection between the two techniques on a per-patient basis. Both dCTA and dCTP identified an additional endoleak in one patient. The diagnostic confidence using dCTP for detection of endoleaks was not significantly superior to dCTA (5.0 [5-5] vs. 4.5 [4-5], respectively; p = 0.11); however, dCTP demonstrated superior diagnostic confidence for endoleak exclusion compared to dCTA (1.0 [1-1] vs 1.5 [1.5-1.5], respectively; p <0.01). Moreover, the dCTP endoleak index was significantly higher than the dCTA index (18.5 [10.8-20.5] vs. 3.5 [5-2.7], respectively; p = 0.02). Conclusions Quantitative analysis of dCTP imaging can aid in the detection of endoleaks and demonstrates a higher endoleak detection rate than triphasic CTA, as well as a strong correlation with visual assessment of dCTA images.