Wong MCY, et al. - An explorative evaluation was conducted of the diagnostic accuracy of color Doppler ultrasound (CD-US) and magnetic resonance urography (MRU) in visualizing crossing vessels (CVs) in pediatric hydronephrosis. The intent was to decide the correct diagnostic pathway in the pre-operative phase. CD-US ought to be be taken into account as the investigation of choice to detect CVs in children with hydronephrosis, in the pre-operative phase. CD-US demonstrated lower costs than MRU, and sedation with infusion of contrast agent was not required. It could be beneficial for the prospective trials to lead a comparison between the two imaging techniques.