Intravenous VasoCT for the Follow-up of Intracranial Aneurysms Treated with Flow-Diverter Stents: Feasibility and Exploratory Correlation with DSA

BACKGROUND AND PURPOSE: There is no consensus regarding the optimal imaging technique for assessing aneurysms treated with flow diverters (FDs). The goal was to evaluate the image quality of IV-VasoCT in the follow-up of aneurysms treated with FDs and to explore its potential for depicting braid stent deformation and vessel lumen modifications. MATERIALS AND METHODS: We retrospectively enrolled patients who underwent FD placement for the treatment of aneurysms, with posttreatment IV-VasoCT at 1-3 months and DSA by at least 6 months. IV-VasoCT image quality assessment evaluated vessel opacification, vessel border, stent radiopacity, stent/vessel contrast, and movement artifacts. Braid stent and parent vessel findings were compared between IV-VasoCT and DSA in terms of neointimal lining, stent foreshortening, fish-mouthing, bumping, and braid collapse. RESULTS: Twenty-six aneurysms were evaluated in 24 patients (woman/man: 15/9), with a median age of 54.5 years (interquartile range: 47.0-59.0 years). The in-consensus image quality reading evaluated: vessel opacification as optimal in 19 cases (73.1%); vessel borders as well-defined in 17 (65.4%); stent radiopacity as well-defined in 25 (96.2%); and stent/vessel contrast as optimal in 20 (76.9%). Compared with DSA, IV-VasoCT diagnosed 2 of 3 (66%) cases of neointimal lining, 2 of 2 (100%) cases of fish-mouth, 1 of 2 (50%) cases of foreshortening, 3 of 6 (50%) cases of bumping, and 2 of 2 (100%) cases of braid collapse. CONCLUSIONS: IV-VasoCT is feasible for the noninvasive follow-up of aneurysms treated with FDs. It may depict modifications in braid stent and vessel neointimal lining, but the presence of coils may reduce its image quality because of artifacts.