Pilot Study: Subtraction CT Iodine Mapping to Detect Endoleak after Endovascular Aortic Aneurysm Repair

Purpose: A well-known complication of endovascular aortic aneurysm repair (EVAR) is endoleak, which can lead to sac expansion thus at risk of rupture. Subtraction CT iodine mapping is a new application of computed tomography (CT) technology that can be used as an adjunctive diagnostic tool for endoleak. This study explores the utility of iodine mapping as a tool for the diagnosis of endoleak.

Materials and Methods: A single-center prospective pilot study of 27 consecutive EVAR patients was conducted. Iodine mapping of subtraction CT technology was compared with traditional triple-phase CT angiography, for the detection of endoleak. Two blinded radiologists interpreted triple-phase CT angiograms compared with subtraction CT iodine mapping overlay in axial imaging. Self-scored (1 to 5) confidence was analyzed in the diagnosis of endoleak.

Results: Majority of identified endoleaks were Type II. Reader 1 had very good agreeability between triple-phase and iodine mapping (κ = 0.92) and identified 1 additional endoleak with iodine mapping. Self-scored confidence in detecting if endoleak present or not was 4.6/5 for triple phase and 4.9/5 for iodine mapping (p = 0.18). Reader 2 had good agreeability between triple-phase and iodine mapping (κ = 0.71) and identified 2 additional endoleaks with iodine mapping. Self-scored confidence in detecting if endoleak present or not was 4.5/5 for triple phase and 4.6/5 for iodine mapping (p = 0.51).

Conclusion: Our pilot study demonstrates subtraction CT iodine mapping is a useful imaging modality adjunct in the diagnosis of endoleak following EVAR; particularly in re-intervention cases which have complex sac artifact. Further validation studies with larger cohorts would be beneficial.

Publication History

Article published online:
02 April 2024