Lacerated Horseshoe Kidney

Horseshoe kidney is a common congenital renal anomaly, with an incidence of 1:500 to 1:1000. It is characterised by fusion of the kidneys at their poles (lower pole in 90%, upper pole in 10%) which produces a horse-shoe shaped structure continuous across the midline. The midline isthmus may be functioning renal parenchyma or non-functioning fibrous tissue. The isthmus cannot ascend past the inferior mesenteric artery and thus the kidney is low in position. The ureters arise anteriorly and there are commonly multiple renal arteries. The complications of horseshoe kidney are 1) urinary stasis with infection or stone formation, due to abnormal ureteric orientation, and 2) predisposition to traumatic injury, due to abnormal position. They are associated with other congenital anomalies and Turner’s syndrome.
Dahnert W. Radiology Review Manual, 5th edition. Lippincott, Williams and Wilkins 2003
Credit: Dr Donna D'Souza
http://www.radpod.org