Patient: December 19 ultrasound month The right renal outer shape is normal in size with smooth surface. The right renal pelvis was separated by 0.6 cm; the left kidney had an enlarged shape with a smooth surface, and the left renal pelvis was dilated to about 5.39×4.03 cm. The 0.95 cm obstruction site in the ureter outside the renal pelvis could not be shown. Intense light spots of varying sizes were seen in both renal pelvises. The right side has a maximum of about 0.34 cm. The bladder fills well and the wall is smooth. Is this condition of the child particularly serious? What should we do? Expert: I cannot make a preliminary judgment from the ultrasound results you provided, probably due to different descriptive habits. Tests such as diuretic nephrography are needed. Patient: What is a diuretic nephrogram? Is it the same thing as an intravenous pyelogram? My doctor suggested MRU when I was preparing to go for an intravenous pyelogram, do I need an MRU? Which test is more informative? Expert: A diuretic nephrogram is a test to understand renal uptake and excretion function through isotope tracers, and also to get some morphological information. Because of its advantages of quantitative understanding of fractional kidney function, understanding of excretion, less radiation dose than intravenous pyelogram, and no risk of allergy due to the use of iodine, diuretic nephrogram is currently the preferred test to understand the kidney function of hydronephrosis. Its disadvantage is that it requires large examination equipment and is difficult to spread. MRU is a magnetic resonance urogram, which rarely provides functional information and is used only in cases where the physician deems it necessary.