Figure 1
![Figure 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1471-2490-10-7/MediaObjects/12894_2009_Article_152_Fig1_HTML.jpg)
A right renal tumor and two renal veins. Oblique view from the ventral to dorsal direction in the arterial phase. The CT scans are arranged from dorsal (A) to ventral (F). A: The right renal artery (RRA) is seen to the right of the inferior vena cava (IVC). B: The upper right renal vein (RRV) can be seen. C: The anterior branches of the RRA and RRV cross each other. D: The lower RRV drains into the IVC closer to the heart than the upper RRV, indicating that these both veins cross over each other. E, F: The tumor is located in the upper pole of the kidney.