Figure 5b. Encrusted bladder catheter. (a) Radiograph obtained 3 weeks after radical retrograde prostatectomy demonstrates a thin rim of peripheral calcification (arrows) on an inflated Foley catheter balloon within the urinary bladder. The tip of the catheter is also encrusted. Surgical clips are related to pelvic lymph node dissection. The balloon was deflated and the catheter uneventfully removed. (b) Radiograph of the pelvis obtained 9 months later shows a large bladder calculus that undoubtedly formed as a result of a nidus of calcific debris left behind when the Foley catheter was removed.