Patient question: I went to the hospital to have a renal dynamic imaging, glomerular filtration, may I ask the director, is there any side effect of this renal dynamic phenomenon? Is it harmful to human body? I looked on the Internet and the word radioactive was mentioned. I am very worried! Wang Xiang replied: Hello, from the ultrasound of 2 months after birth, it should be more likely to be left ureteral end obstruction or left giant ureteropathy. The ultrasound, MRI and other imaging tests are only morphological, so the doctor will recommend your baby to do isotope renogram, because this test can show the respective functions of the two kidneys, that is, calculate the glomerular filtration rate of the split kidney, to estimate the function of the two kidneys, to see if they are affected. The function of both kidneys to see if there is any damage. Then we can decide whether surgery is needed now. Then isotope nephrography, also known as renal dynamic imaging, including diuretic nephrography which requires further diuresis, is slightly radioactive, mainly because it requires the injection of a contrast agent from the baby’s vein, which is labeled with isotopic elements in a very small amount, just the dose of a chest X-ray or even less. It will be metabolized from the baby’s body and excreted in the urine in a few hours. Parents should not worry too much.