Figure 7c. Large right upper pole renal cyst in a 57-year-old man not appreciated on (a) a routine anteroposterior IVU image but readily seen on (b) an anteroposterior tomogram. (c) Double-contrast cyst puncture radiograph obtained cross-table with the patient in the lateral prone position shows the walls to be smooth (arrows in b and c). The layer between the contrast material and the air (A) is normal cyst fluid.