Fig. 5

A Segmentation of a 4.2 cm diameter tumor located in the lower pole of the right kidney (outlined in orange) on pre-ablation axial T2-weighted MR imaging. B Segmentation of the corresponding ice ball (outlined in blue) on post-ablation axial T1-weighted MR imaging. C Overlay of pre-ablation and post-ablation images after co-registration (left) and resulting 3D margin calculation (right). Volumetric assessment shows predicted incomplete ablation at medial side (red) with MTM of − 6 mm. D Follow-up axial T2-weighted MR imaging at 2 months (left) after cryoablation shows ablation zone (white arrows) with suspected incomplete coverage on medial side (red arrows). Six months follow-up MRI (right) confirms local tumor progression (red arrow) at the medial side