Abstract Body (Do not enter title and authors here): Evaluation of carotid artery stenosis (CAS) is an essential step of preprocedural planning. Computed tomography angiography (CTA) is currently widely utilized, however three-dimensional rotational angiography (3DRA) has emerged as an alternative offering potential advantages. However, direct comparisons between modalities are limited.

To assess the agreement and correlation between CTA and 3DRA in quantifying the CAS severity.

This single-center, prospective study included 154 patients referred for carotid artery stenting (CS) between 2016 and 2021 at a tertiary care center in Texas. All patients underwent CTA and 3DRA imaging. Measurements of the common carotid artery (CCA) and internal carotid artery (ICA) diameters in anteroposterior (AP) and lateral (LAT) views, as well as percentage luminal stenosis were obtained using both imaging modalities. Bland–Altman analysis was used to assess agreement. Pearson’s correlation coefficient (r) was calculated to assess linear correlation.

There was strong correlation between modalities across all measurements.. The correlation was strong for CCA diameter, in both AP and LAT planes (r = 0.99). ICA measurements also showed high correlation (AP, r = 0.95; LAT, r = 0.97). The limits of agreement for ICA were broader compared to CCA. CTA overestimated the degree of stenosis compared to 3DRA, (mean difference +4.34%; r = 0.99).

In patients undergoing evaluation for CS, CTA and 3DRA exhibited strong correlation in vessel diameter and stenosis measurements. An overestimation of stenosis by CTA was observed. Awareness of this modality-specific difference is essential. The 3DRA potentially offers important procedural advantages (identification of the optimal angle selection for intervention and minimal contrast volume for the intervention). This makes 3DRA particularly valuable in patients with advanced kidney disease.