Pyelocalyceal diverticulum: the imaging spectrum with emphasis on the ultrasound features.

Clinical and imaging data of 11 patients with pyelocalyceal diverticulum were retrospectively examined. Four patients suffered from ipsilateral flank pain, one from recurrent urinary tract infection and the other six from unrelated symptoms. All patients underwent ultrasound as the initial imaging study. In two cases ultrasound was the only examination performed. Additional imaging studies were obtained in the other nine patients (abdominal radiography in six cases, intravenous urography (IVU) in five and CT in four). Ultrasound suggested the diagnosis of pyelocalyceal diverticulum in eight cases owing to the presence of echogenic and mobile material within the cyst-like lesion. In three cases the ultrasound appearance was similar and indistinguishable from a simple cyst and the diagnosis was made by another imaging study IVU in two cases and CT in one). We suggest that ultrasound examination is the best imaging method for the diagnosis of a pyelocalyceal diverticulum, and no further imaging modalities are required when mobile echogenic material is seen. In uncertain cases, another relatively inexpensive imaging study should be added such as abdominal radiography or IVU.