A. Duplicated collecting system
Duplication of the collecting system is the most common anomaly of the urinary tract. On closer inspection of the image in figure 1a, the stones are not aligned with the course of one ureter. In figure 2b, the arrow points to the second stone seen just medial to the ureter. Often in an effort to reduce radiation by using the settings of “pulse” and “low dose” mode, the very radiopaque appearing stones on KUB are only seen faintly on intra-operative imaging. The patient went back to the operating room where she was found to have a completely duplicated collecting system. The second stone was found in the proximal ureter of the upper pole moiety and was fragmented and removed with stent placement (figure 2b).
Ureteral duplication and its complications. RadioGraphics 1997; 17:109-27
Dr. Sorokin, Assistant Professor at the University of Massachusetts, Worcester, MA, is section editor for Urology Times Clinical Quiz.