Figure 18a. Multilocular cystic nephroma in a 32-year-old man. (a) Excretory urogram shows marked splaying of the upper and lower caliceal systems (arrows) with mild dilatation of the upper pole calix. (b) Axial MR image obtained with true fast imaging with steady-state precession (6.3/3.0, 70° flip angle) shows a high-signal-intensity cystic mass in the left kidney. Note the numerous fine septations without solid components. (c) Coronal gadolinium-enhanced T1-weighted MR image (130/4.1) shows herniation of the cystic mass (arrow) into the renal sinus.