High-Resolution C-arm Computed Tomography for Evaluation of Stent Expansion and Apposition after Intracranial Stent Implantation.

Objective: C-arm computed tomography (CT) has always played an important role in neurointerventional surgery, in this study, we aimed to investigate the value of high-resolution C-arm CT in evaluating stent expansion and apposition in carotid arteries of Guangxi Bama piglets.

Methods: Twenty-four stents were implanted in the carotid arteries of 24 Guangxi Bama piglets. High-resolution C-arm CT was performed to evaluate stent expansion and the quality of processed images, followed by three-dimensional digital subtraction angiography (3D-DSA). The DSA and high-resolution C-arm CT images were transmitted to a postprocessing workstation for image reconstruction (dual-volume reconstruction method). High-resolution C-arm CT reconstructed images after diluted contrast agent injection (diluted contrast method) were also acquired. In addition to assessing radiation exposure, the accuracy of stent apposition assessment by the two methods was compared, using intravascular ultrasound as the reference standard. Adverse events during and within 24 hours after the procedure were recorded.

Results: One stent was incompletely expanded, while the remaining 23 stents were fully expanded without disruption. The image quality of high-resolution CT was grade I in most cases (n=22/24). Both methods clearly demonstrated stent apposition with a consistency of 100%. However, the dual-volume reconstruction method was associated with significantly higher radiation exposure (p<0.001). Mild-tomoderate vasospasm occurred in four piglets when the diluted contrast method was used. Overall, no serious complications occurred in this study.

Conclusion: High-resolution C-arm CT enables clear microstructure visualization and can be used in combination with different postprocessing techniques to accurately assess the apposition of intracranial stents.