Horseshoe kidney with unilateral obstruction

Case contributed by Dr Alexandra Stanislavsky


Sudden onset left flank pain. No past medical history.

Patient Data

Age: 40 years
Gender: Female

Erect and supine abdominal x-rays.  A cluster of calcifications is identified just lateral to the left L2 spinous process. The adjacent soft tissue contour has the appearance of a kidney, however, is more medially located than would be expected. 


A non contrast renal tract CT was performed.

There is continuity of the renal parenchyma across the midline, in keeping with a horseshoe kidney.  The cluster of calcifications seen on the x-ray is confirmed to be in the left renal pelvis.  The left ureter is dilated, due to an obstructing calculus located just proximal to the vesicoureteric junction.

Delayed CT IVP images demonstrate the two halves of the horseshoe kidney joined at a parenchymal isthmus. There is sharp delineation between the normally excreting right kidney, and the delayed nephrogram of the obstructed left kidney, with virtually no excretion into the left collecting system.

Annotated image

Annotated x-ray findings

Case Discussion

Horseshoe kidney with ureteric calculus causing unilateral obstruction with a delayed nephrogram.

PlayAdd to Share

Case information

rID: 19262
Published: 21st Aug 2012
Last edited: 3rd Sep 2020
System: Urogenital
Inclusion in quiz mode: Included