CT findings of the main pathological conditions associated with horseshoe kidneys.

Horseshoe kidney (HSK) is the most common renal fusion anomaly, with a prevalence of 0.25% among the general population. It consists of kidney fusion across the midline. HSK can be present as an isolated condition in 30%, but there is a wide variety of associated abnormalities. The most frequent include ureteropelvic obstruction, lithiasis and infections. There is also a higher risk of kidney lesions in trauma and an increased incidence of malignancies. Awareness of embryology and anatomy is essential to assess and understand the complications affecting HSK. CT is an excellent method for identification of its main findings.