What is an ultrasound?

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 gall bladder, 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 transvaginal or pelvic ultrasound?

An ultrasound of the pelvis or transvaginal ultrasound is used to examine the uterus and ovaries in a female. (See illustration.) Most of the time, the exam will be done using the transvaginal method. This method is preferred due to the higher quality of images obtained that gives the doctors optimal results. During this approach, a specialized transducer is inserted in the vaginal canal about 2 to 3 inches. However, there are cases in which a patient cannot tolerate this exam, is a pediatric patient, or chooses not to do this method. In those cases, the patient will be asked to fill their bladder and a transabdominal approach will be used.

On the day of the test

You may eat or drink as normal the day of the exam. There is no prep for the transvaginal approach. If you need to do the transabdominal approach only, you will need to drink the following amount of water one hour before exam and not use the restroom.

  • Ages newborn to toilet-trained —Encourage fluids one-half hour before the exam.
  • Ages toilet-trained to 4 years — Have your child drink 8-10 ounces of fluid one-half hour before the exam.
  • Ages 5-8 years — Have your child drink 16 ounces of fluid one-half hour before the exam.
  • Ages 9-12 years — Have your child drink 24 ounces of fluid one-half hour before the exam.
  • Ages 13-18 years — Have your child drink 24 ounces of fluid one hour before the exam.
  • Age 18 and older — Drink 32 ounces of fluid one hour before the exam.

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. During the transabdominal approach, 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. During the transvaginal approach, a specialized transducer is inserted in the vaginal canal about 2 to 3 inches. This transducer is covered with a plastic protector before each patient and a sterile, cold gel is applied to the outside.

The ultrasound will take about 45 minutes to complete.

After the test

The results of your ultrasound are usually available within 24 hours after your test, Monday through Friday.

Your ordering physician will discuss the test results with you.


  • American College of Radiology and Radiological Society of North America via radiologyinfo.org. Ultrasound-Pelvis Accessed 4/22/2015.
  • F, Calver LE. Chapter 2. Techniques Used for Imaging in Gynecology. In: Hoffman BL, Schorge JO, Schaffer JI, Halvorson LM, Bradshaw KD, Cunningham F, Calver LE. eds. Williams Gynecology, 2e. New York, NY: McGraw-Hill; 2012. library.ccf.org Accessed 4/22/2015.

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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 4/22/2015...#4993