Background and purpose To assess the performance of dual energy unenhanced CT in the detection of acute ischemia after mechanical thrombectomy.

Methods Retrospective study, approved by the local institutional review board, including all patients that underwent intra-arterial thrombectomy in our institution over a period of 2 years. The presence of acute ischemia and hemorrhage was evaluated by three readers. Sensitivity and specificity of the non-contrast CT weighted sum image (NCCT) and the virtual non-contrast reconstructed image (VNC) were estimated and compared using generalized estimating equations to account for the non-independence of regions in each patient.

Results 58 patients (27 women and 31 men; mean age 70.4 years) were included in the study, yielding 580 regions of interest. Sensitivity and specificity in detecting acute ischemia were higher for all readers when using VNC, with a significant increase in sensitivity for two readers (p<0.001 and 0.01) and a significant increase in specificity in one reader (p<0.001). Specificity in detecting hemorrhage was excellent for all readers.

Conclusions Dual energy unenhanced CT VNC images were superior in the identification of acute ischemia in comparison with NCCT.