What is an ultrasound?
Ultrasound (also known as sonography or ultrasonography) is a diagnostic procedure that transmits high-frequency sound waves, inaudible to the human ear, through body tissues. The echoes are recorded and transformed into video or photographic images of the internal structures of the body.
Ultrasound images help in the diagnosis of a wide range of diseases and conditions. Ultrasound is used to create images of soft tissue structures, such as the gallbladder, liver, heart, kidney, female reproductive organs -- and even of fetuses still in the womb. Ultrasound can also detect blockages in the blood vessels.
Ultrasound may be used with other diagnostic procedures or by itself. Studies have shown that ultrasound is not hazardous. There are no harmful side effects. In addition, ultrasound does not use radiation, as X-ray tests do.
Before the test
The preparation for this test will depend on the type of ultrasound procedure your doctor has ordered. Some preparations include drinking a quart of water before the test to obtain better images. Other preparations may include eating a fat-free dinner the night before the test, or possibly fasting. The doctor, nurse, or receptionist will give you complete instructions prior to the exam.
What is a kidney ultrasound?
A kidney ultrasound looks at the right and left kidney and also the bladder. Your doctor may also need a “post void” done with this exam. This requires you to come with a full bladder to get a volume of the bladder before and after you empty it.
On the day of the test
You may eat or drink as normal the day of the exam. Your doctor may need a post void of the bladder which will require you to drink 1 liter (30oz) of water an hour before the exam and not use the restroom until after.
Your ultrasound test will be performed by a registered, specially trained, technologist and interpreted by a board-certified radiologist.
During the test
You will lie on a padded examining table. A warm, water-soluble gel is applied to the skin over the area to be examined. The gel does not harm your skin or stain your clothes. A probe is gently applied against the skin. You may be asked to hold your breath several times or roll on your side.
The ultrasound will take about 20-30 minutes to complete.
After the test
The results of your ultrasound are usually available within 24 hours after your test. Your ordering physician will discuss the test results with you.