Dual-energy CT angiography in imaging surveillance of endovascular aneurysm repair - Preliminary study results

Stavros Charalambous; Kostas Perisinakis; Nikolaos Kontopodis; Antonios E Papadakis; Thomas G Maris; Christos V Ioannou; Apostolos Karantanas; Dimitrios Tsetis

doi:10.1016/j.ejrad.2022.110165

Dual-energy CT angiography in imaging surveillance of endovascular aneurysm repair - Preliminary study results

Eur J Radiol. 2022 Mar:148:110165. doi: 10.1016/j.ejrad.2022.110165. Epub 2022 Jan 19.

Authors

Stavros Charalambous¹, Kostas Perisinakis², Nikolaos Kontopodis³, Antonios E Papadakis², Thomas G Maris², Christos V Ioannou³, Apostolos Karantanas⁴, Dimitrios Tsetis⁵

Affiliations

¹ Interventional Radiology Unit, Department of Medical Imaging, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece; Department of Medical Imaging, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece; Department of Radiology, School of Medicine, University of Crete, P.O. Box 2208, Heraklion 71003, Crete, Greece.
² Department of Medical Physics, University Hospital of Heraklion, School of Medicine, University of Crete, P.O. Box 2208, Heraklion 71003, Crete, Greece.
³ Vascular Surgery Unit, Department of Cardiothoracic and Vascular Surgery, University Hospital of Heraklion, School of Medicine, University of Crete, P.O. Box 1352, Heraklion 71110, Crete, Greece.
⁴ Department of Medical Imaging, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece; Department of Radiology, School of Medicine, University of Crete, P.O. Box 2208, Heraklion 71003, Crete, Greece.
⁵ Interventional Radiology Unit, Department of Medical Imaging, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece; Department of Medical Imaging, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece; Department of Radiology, School of Medicine, University of Crete, P.O. Box 2208, Heraklion 71003, Crete, Greece. Electronic address: tsetisd@uoc.gr.

PMID: 35081491
DOI: 10.1016/j.ejrad.2022.110165

Abstract

Purpose: To investigate the value of dual-energy CT imaging to discriminate low- from high- risk type II endoleaks (T2EL) after endovascular aneurysm repair (EVAR).

Method: Study participants were consecutive patients referred for CT at 1-month post-EVAR. CT imaging acquisition included a dual-energy CT angiography (DECTA) and a delayed single-energy CT (SECT) imaging. Patients diagnosed with T2EL were re-examined at 6-months post-EVAR to assess the aneurysm sac growth (ASG). Upon ASG recorded, patients were categorized as having low- (group A) or high- risk (group B) T2EL. DECTA image data were employed to calculate the normalized effective atomic number (NZ_eff), the normalized iodine concentration, the slope of HU_endoleak/HU_aorta against monochromatic energy, the dual-energy index and an improvised endoleak index (EI) for each T2EL. Statistical analysis was employed to compare all above parameters regarding their ability to differentiate low- from high- risk T2EL.

Results: Among 40 patients examined at 1-month post-EVAR, 14 patients were diagnosed with T2EL. NZ_eff and EI were found to be significantly lower in group A. NZ_eff was found to have the highest power to discriminate high-risk T2EL with an area-under-curve of 86.7%, showing100% specificity and 60% sensitivity. The optimal contrast-to-noise ratio for T2EL demonstrated a median peak conspicuity level at 54-keV. The mean effective dose from DECTA and SECT scans was 27.8% lower compared to the sum of three SECT acquisitions.

Conclusions: NZ_eff and EI were found to have a significant power in predicting the aggressiveness of T2EL lesions. Virtual monochromatic images at 54-keV may enhance T2EL detection efficiency.

Keywords: Aortic aneurysm; Computed tomography; Dual energy CT; Endoleak; Endovascular aneurysm repair.

MeSH terms

Aortic Aneurysm, Abdominal* / surgery
Blood Vessel Prosthesis Implantation*
Computed Tomography Angiography
Embolization, Therapeutic*
Endoleak / diagnostic imaging
Endovascular Procedures*
Humans
Retrospective Studies
Time Factors
Treatment Outcome