OBJECTIVE: Cerebral contrast staining (CCS) postendovascular procedures may mimic subarachnoid hemorrhage. This study investigates CCS frequency and risk factors using dual-energy computed tomography (DECT) following coil embolization of unruptured intracranial aneurysms. METHODS: A retrospective analysis included 232 patients undergoing coil embolization and immediate DECT imaging between October 2018 and March 2023. CCS was defined as hyperattenuation on iodine overlay images absent on virtual noncontrast images. Logistic regression identified predictors of CCS. RESULTS: CCS occurred in 95 patients (40.9%), predominantly in anterior circulation aneurysms (48.1%) compared to posterior circulation (14.3%, P = 0.002). High CCS rates occurred particularly in posterior communicating (59.1%) and anterior communicating/anterior cerebral artery aneurysms (59.0%). Low-osmolar contrast media had higher CCS incidence (56.4%) compared to iso-osmolar media (30.4%, P <
0.002). CCS-positive patients had higher contrast volume (186.35 ± 46.62 mL vs. 171.62 ± 34.89 mL
P = 0.009) and longer procedures (158.41 ± 41.25 vs. 135.28 ± 35.07 min, P <
0.002). Multivariate analysis identified posterior communicating artery aneurysms, low-osmolar contrast media, procedure duration, and contrast volume as independent CCS predictors. Demographic factors and blood pressure variability were unrelated. One transient contrast-induced encephalopathy case occurred
no hemorrhages were identified. CONCLUSIONS: CCS is common after coil embolization, especially with longer procedures, anterior aneurysms, and low-osmolar contrast media. DECT effectively differentiates CCS from hemorrhage, potentially reducing unnecessary follow-up imaging.