Virtual resection plane. We generated surface models of the urinary tract (A) and tumor (B) regions. We also generated multiple kidney regions that had 1 mm (E), 3 mm (F), and 5 mm (G) margins from the tumor. We also generated transparent (C) and CT-image renderings (D) of the kidney model. The CT-image rendering (D) allowed observance of the CT value on the resection plane.