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Computed tomography (CT) and Magnetic resonance (MR) are the standard imaging modalities for the evaluation of liver tumors after interventional radiologic treatment (thermal ablation, embolization, chemoembolization). Both CT and MR are based on intravenous administration of the appropriate contrast medium (iodine- or gadolinium-based, respectively), to differentiate the enhancing (viable) component of the treated tumor from the non-enhancing (necrotic) component. The diagnosis of complete necrosis of the treated tumor is based on complete elimination of tumoral enhancement in all phases of the study. This feature correlates favorably with histologic necrosis of the tumor; however, in some cases with imaging diagnosis of complete necrosis, histology has revealed foci of viable neoplasm (usually measuring only a few millimeters). CT and MR can also depict areas of non-tumoral enhancement in liver segments adjacent to the treated tumors; these findings are caused by reactive hyperemia or local hemodynamic changes induced by the interventional treatment. CT and MR can diagnose almost all of the complications which are associated with interventional treatment, thanks to their specific imaging features. Compared to CT, MR has a slightly superior accuracy in the diagnosis of residual tumor after interventional treatment. Contrast-enhanced ultrasound, when available, has a valuable complementary role in post-interventional imaging, but cannot replace CT and MR. [ABSTRACT FROM AUTHOR]