Presentation
Renal colic.
Patient Data
Both kidneys are malrotated, fused at their lower poles forming a parenchymal isthmus (or bridge) crossing the midline anterior to the aorta and IVC. Duplex collecting system of the right kidney with two ureters that apparently drained separately into the bladder. Dilatation of the left renal cavities and lower collecting system of the right kidney.
Renal stones of the upper calyces measuring 3 mm on the right (density = 300 HU) and 7 mm on the left (density = 800 HU).
Case Discussion
CT urography of renal stones in a patient with horseshoe kidneys with duplex collecting system of the right kidney.