Ultrasound is a test that uses sound waves to create an image of the inside of your body. This test can be used by itself or in combination with other tests to help diagnose many different medical conditions. When ultrasound is used to look at the kidneys or bladder, it’s called a renal ultrasound.
A kidney ultrasound (renal ultrasound) is an imaging test that allows your healthcare provider to look at your right and left kidney, as well as your bladder. The kidneys are the filtration system of your body. They filter the waste products out of your blood. The waste products then leave your body as urine.
Your healthcare provider may also need a “post void” done with this exam. This requires you to come to the test with a full bladder so that the provider can get a volume of your bladder before and after you empty it.
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Ultrasound is an imaging test that uses high-frequency sound waves to see inside your body. This diagnostic test sends these sound waves — inaudible to the human ear — through your body tissues. The echoes are recorded and transformed into video or photographic images of the internal structures of the body. You might also hear this test call sonography or ultrasonography. Many people associate this test with pregnancy because it’s often used to look at a developing fetus. However, an ultrasound can be used for many reasons and it’s a useful diagnostic tool.
Painless, an ultrasound is usually done on top of your skin (non-invasive). Ultrasound images help in the diagnosis of a wide range of disease and conditions. Some organs that can be seen on an ultrasound include the:
Ultrasound can also detect blockages in your blood vessels.
Your healthcare provider might use an ultrasound by itself or with other diagnostic tools. Studies have shown that it’s not hazardous to get an ultrasound. There are no harmful side effects. Also, unlike X-ray tests, ultrasound doesn’t use radiation.
The preparation for this test will depend on the type of ultrasound procedure your healthcare provider has ordered. Some things you might need to do to get ready for your ultrasound could include:
In some cases, you may not need to do anything before your ultrasound. Your healthcare provider will let you know exactly what you need to do before the test. If you have any questions leading up to your ultrasound appointment, call your provider’s office to learn more about how to prepare.
Unless told otherwise by your healthcare provider before the ultrasound, you can eat or drink as normal on the day of your test. If your provider needs a post void of your bladder, you’ll be required to drink 30 ounces of water an hour before the exam and not use the restroom until after the ultrasound.
Your ultrasound test will be performed by a registered, specially trained, technologist and interpreted (read) by a board-certified radiologist.
During the kidney ultrasound, you will be asked to lie on a padded examining table. The provider performing the ultrasound will apply a warm, water-soluble gel to your skin over the area that’s being examined. This gel won’t harm your skin or stain your clothes. A probe is then gently applied against your skin. You may be asked to hold your breath several times or roll on your side during the test. Typically, the ultrasound will take about 20 to 30 minutes to complete.
In most cases, the results of your ultrasound are available within 24 hours after the test, Monday through Friday. The healthcare provider who ordered the test will usually discuss the test results with you.
Last reviewed by a Cleveland Clinic medical professional on 10/27/2020.
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