- Both kidneys are fused together in early embryonic life.
- Term horseshoe kidney refers to the appearance of the fused kidney
- Fusion occurs at the lower poles in about 95% cases.
- This region of fusion, called the isthmus, is usually composed of renal parenchymal tissue. However, in many cases, it may consist of fibrous tissue. The isthmus usually lies anterior to posterior to the inferior mesenteric artery.
- The renal pelves are usually malrotated and lie anteriorly or laterally.
- Ureteropelvic junction obstruction (UPJ)
- Recurrent infections occur because of urine stasis and associated vesicoureteral reflux.
- Nephrolithiasis related to UPJ obstruction or infection may occur.
- An increased risk of trauma to the isthmus exists because of its position anterior to the spine.
- Some evidence suggests an increased incidence of certain renal tumors in horseshoe kidney.
 Imaging Findings
Patient #1: CT images demonstrate a horseshoe kidney
Patient #2: CT images demonstrate a horseshoe kidney
 See Also
 External Links
- Irshad, Abid . E-medicine radiology article