What is a kidney ultrasound? 

A kidney ultrasound is an imaging test that uses sound waves to look at your kidneys. It can check the size, shape, and location of your kidneys. It also shows how well blood is flowing to your kidneys. 

The technologist uses a device called a transducer to make the images of your kidneys. The transducer sends out sound waves that bounce off your kidneys. The sound waves are too high-pitched for you to hear. The transducer then picks up the bounced sound waves. These are made into pictures of your kidneys.   

Ultrasound is extremely safe and does not use any ionizing radiation. Ultrasound is widely available, easy to use and less expensive than any other imaging methods. 

Why might I need a kidney ultrasound? 

You may need a kidney ultrasound if your healthcare provider thinks you may have a problem in your kidneys. These problems include: 

  • Cyst 
  • Tumor 
  • Abscess 
  • Blockage 
  • Collection of fluid 
  • Infection 
  • Kidney stone 
  • See how blood is flowing to the kidneys through the renal arteries and veins 

Your provider may also use ultrasound after a kidney transplant to see how well the transplanted kidney is working. A kidney ultrasound is not painful. You may have some discomfort from having to remain still during the test. 

What happens during a kidney ultrasound? 

Generally, a kidney ultrasound follows this process: 

  1. You will be asked to remove any jewelry or other objects that may get in the way of the scan. 
  2. You may be asked to remove clothing. If so, you will be given a gown to wear. 
  3. You will lie on an exam table on your back and you will be told when to move positions for different kidney views. 
  4. The technologist will put a clear warm gel on the skin over the area to be looked at.  
  5. The technologist will press the transducer against the skin and move it over the area being studied.  
  6. If your bladder is looked at, you will be asked to empty your bladder after scans of the full bladder are done. You will have more scans done of the empty bladder. 
  7. Once the test is done, the technologist will wipe off the gel.