Pediatric Renal Ultrasound (Kidneys, Ureters, Bladder)

What is it?

A renal ultrasound is a safe and painless test that uses sound waves to make images of the kidneys, ureters, and bladder. This test does not involve any radiation.

During the examination, an ultrasound machine sends sound waves into the kidney area and images of the kidneys and related organs are recorded on a computer. Physicians order renal ultrasounds when there’s a concern about certain types of kidney or bladder problems. Renal ultrasounds can show:

  • the size of kidneys
  • signs of injury to the kidneys
  • abnormalities present since birth
  • the presence of blockages or kidney stones
  • complications of a urinary tract infection (UTI)
  • cysts or tumors


Usually, you don’t have to do anything special to prepare for a renal ultrasound, although the doctor may ask that your child not eat or drink anything for several hours before the test. You should tell the technician about any medications your child is taking before the test begins.

Some younger children may be afraid of the machinery used for the ultrasound test. Explaining in simple terms how the renal ultrasound test will be conducted and why it’s being done can help ease your child’s fears. You can tell your child that the equipment takes pictures of his or her kidneys. Encourage your child to ask the technician questions and to try to relax during the procedure, as tense muscles can make it more difficult to get accurate results.

During the Exam

Parents are usually able to accompany their child to provide reassurance and support. The room is usually dark so the images can be seen clearly on the computer screen.

A technician (sonographer) trained in ultrasound imaging will spread a clear, warm gel on your child’s abdomen over the kidney area. This gel helps with the transmission of the sound waves. The technician will then move a small wand (transducer) over the gel. The transducer emits high-frequency sound waves and a computer measures how the sound waves bounce back from the body. The computer changes those sound waves into images to be analyzed. The procedure generally takes less than 30 minutes.

During the procedure, your child may feel slight pressure on the abdomen as the transducer is moved over it. Your child will need to lie still so the sounds waves can reach the area effectively. The technician may ask your child to lie in different positions or hold his or her breath briefly. Babies might cry, especially if they are restrained, but this won’t interfere with the procedure.