Dyna three-dimensional imaging enables reliable evaluation of neointimal formation after flow diverter treatment

Background Flow diverter stent (FDS) treatment is an effective option for wide-necked intracranial aneurysms, but adequate neointimal formation and stent apposition are critical to prevent thromboembolic complications. Non-invasive, reliable imaging techniques for assessing neointimal formation remain limited. This study aimed to evaluate the utility of Dyna-3D imaging in assessing neointimal formation after FDS treatment and to compare its performance with conventional 2D-DSA. Methods This retrospective study included 61 patients with unruptured intracranial aneurysms treated with FDS between August 2019 and October 2024. Radiological follow-up was performed 3–6 months post-procedure using both 2D-DSA and Dyna-3D imaging. Neointimal coverage was classified into Groups A–C based on the positional relationship between the stent wires and the vessel wall (Group A = wire outside; Group B = partial overlap; Group C = the vessel wall outside). Interobserver agreement, imaging accuracy, and associated clinical factors were analyzed. Results Complete neointimal formation (Group A) was identified in 51 cases (83.6%; 95% CI 72.4–90.8) using Dyna-3D and 21 cases (34.4%; 95% CI 23.7–47.0) using 2D-DSA ( P < .0001). Dyna-3D demonstrated superior interobserver agreement (Cohen's κ =0.893; 95% CI 0.75–1.00) compared to 2D-DSA ( κ =0.459; 95% CI 0.28–0.64) in the evaluation of neointimal formation. Multivariate analysis identified younger age as a significant factor associated with Group A classification across both modalities (2D-DSA: OR 0.93, 95% CI 0.88–0.98, P = .008; Dyna-3D: OR 0.90, 95% CI 0.8–0.97, P = .018). No thromboembolic or hemorrhagic complications were identified during follow-up. Conclusion Dyna-3D imaging provides superior visualization of neointimal formation compared to conventional 2D-DSA and enables comprehensive circumferential assessment of stent apposition. These findings suggest that Dyna-3D may offer a useful tool for guiding post-FDS treatment management, including the potential for age-adjusted optimization of antiplatelet therapy duration.