Dual-energy CT fusion imaging improves ice-ball visualization in bone during spinal cryoablation in porcine cadavers

OBJECTIVE: We evaluated ex vivo feasibility of ice-ball visualization during bone cryoablation using dual-energy computed tomography (DECT). MATERIALS AND METHODS: in bone and adjacent tissues. Fused ED and VNCa images were assessed for each vertebra. For one pig, the fused ED and VNCa images were compared with post-ablation magnetic resonance imaging (MRI). RESULTS: images. The best contour delineation was observed on ED images for soft tissues, whereas the ice-ball was detectable in bone only on VNCa images, with poorer but acceptable contour delineation. Significant (p ≤ 0.039; effect size (ES) ≥ 0.84) changes in HU and ED were observed for the adjacent soft tissue. For bone, significant (p ≤ 0.043; ES ≥ 0.073) changes were found of ED and HU* on VNCa. ED/VNCa fusion improved ice-ball delineation in bone, confirmed by comparison with MRI. CONCLUSION: The fusion of spectral ED and VNCa images could show potential in improving the visualization of the ice-ball during bone cryoablation. RELEVANCE STATEMENT: Fusion of electron density and virtual non-calcium images enhances the ice-ball visualization in bone during spinal cryoablation. KEY POINTS: The lack of visibility of the ice-ball in the bone during cryoablation represents a limitation for the safety of adjacent structures at risk. In bone, the ice-ball was detectable only on virtual non-calcium (VNCa) images, but the quality of its contour delineation was poorer. Electron density and VNCa fusion images improved ice-ball visualization and delineation in bone, as confirmed by comparison with MRI.