Quantitative assessment of renal obstruction in multi-phase CTU using automatic 3D segmentation of the renal parenchyma and renal pelvis: A proof of concept

•The algorithm enables accurate segmentation of the renal parenchyma and renal pelvis.•The algorithm estimates the amount of contrast media in the various CTU phases.•Objective indicators were developed, to alert the presence of renal obstruction.•In hydronephrotic kidneys the total amount of contrast media did not decrease.•In hydronephrotic kidneys the drainage time, T1/2, was longer than 20 min.