CT urography features are consistent with right renal peripelvic cysts (a type of renal sinus cyst), which can be easily confused with its most common rival (i.e. hydronephrosis), on an ultrasound examination. Multiphasic contrast-enhanced CT scan (particularly its renal excretory phase), is the best imaging modality for differentiating the renal peripelvic cysts from hydronephrosis. Rarely, these entities can coexist (like this case) and need special attention while interpreting the scan to avoid any error.