Figure 11c. Perinephric hematoma after renal RF ablation. (a, b) Unenhanced (a) and contrast material-enhanced (b) CT scans obtained shortly after RF ablation demonstrate a large perinephric hematoma (arrow). (c) Follow-up CT scan obtained 5 months later shows the hematoma with mild interval shrinkage and a second tumor on the contralateral kidney (arrow).