What to expect with your Ultrasound exam.
Diagnostic Ultrasound is the use of high frequency sound waves to visualize structures within the body. A small device called a transducer is used to send sound waves into the body, which are then reflected off of internal structures. The returning sound waves (echoes) are then sent back to the same transducer and the attached equipment electronically changes the echoes into a picture (image) of your internal structures. If your blood flow is what is being studied, audible sound as well as an image can be produced.
What is Ultrasound?
Ultrasound is like ordinary sound except it has a frequency (or pitch) higher than human beings can hear. When sent into the body from a transducer resting on a patient’s skin, the sound is reflected off internal structures. The returning echoes are received by the transducer and converted by an electronic instrument into an image of the internal structures on a viewing screen. These continually changing images can be recorded on film, paper, videotape, or computer. Diagnostic ultrasound imaging is commonly called sonography or ultrasonography. In an abdominal examination, ultrasound produces images of the major organs, including the liver, gallbladder, bile ducts, pancreas, spleen, kidneys, and large blood vessels.
What is Doppler Ultrasound?
Doppler ultrasound is a special form of ultrasound used in evaluating blood flow to the various organs of the body. It can be displayed in variable formats: an audible sound, a spectrum of colors within blood vessels, or a graph showing changes in velocity.
Why should I have an Ultrasound Exam?
There are many reasons for examining the abdomen with ultrasound, among the more common reasons are:
- To look for causes of upper abdominal pain, including gallstones, cholecystitis, pancreatitis, kidney stones, or blockage in blood vessels of the intestines;
- To look for causes of lower abdominal pain, including appendicitis, inflammation of the small and large intestines, and hernias;
- To look for abnormalities that may be present in the abdominal organs, such as masses or enlargements in the spleen or liver;
- To evaluate the nature of a mass that may have been felt by the examining doctor or seen on other radiologic exams;
- To evaluate for enlargement of the liver or spleen.
- To determine the cause of kidney failure, such as kidney disease, obstruction of the kidneys, or blockage of the kidneys’ blood vessels;
- To evaluate for the cause of jaundice or abnormal liver enzymes;
- To look for enlargements (aneurysms) of the abdominal aorta;
- To evaluate for problems of flow in the blood vessels of the various abdominal organs.
An ultrasound examination may not provide all the information your doctor needs. In these cases, additional studies may be required.
Are there any special preparations for the exam?
Your doctor will probably tell you to refrain from eating, drinking, smoking, or chewing gum for 8 hours prior to the exam This is because these actions increase the amount of abdominal gas, which may alter blood flow in upper abdominal organs, and cause the gallbladder to contract, preventing an adequate ultrasound examination.
Will it hurt?
There is no pain involved in an ultrasound examination of your abdomen. The transducer is placed on the skin surface after a gel is applied to your abdomen to provide better contact. The gel may feel cool and may temporarily stain clothes, so you may want to wear easily washable clothing. The room is usually darkened during the examination.
How long will it take?
The length of time for the examination varies with the complexity of the exam and the specific reasons for which it was requested. After the exam, you can safely drive home and eat and drink normally.
Who will perform the exam?
In most cases, a sonographer or a vascular technologist trained in ultrasound will examine you. He or she obtains and records a series of images. The doctor then reviews the images, may discuss your exam with the sonographer or vascular technologist, and will then issue an official interpretation. This interpretation may not be available immediately after you have your exam. In some cases, the doctor will also examine you to confirm or resolve uncertain or unclear findings.
Is Ultrasound safe?
There are no known harmful effects associated with the medical use of sonography. Widespread clinical use of diagnostic ultrasound for many years has not revealed any harmful effects. Studies in humans have revealed no direct link between the use of diagnostic ultrasound and any adverse outcomes. Although the possibility exists that biological effects may be identified in the future, current information indicates that the benefits to patients far outweigh the risks, if any, that may be present.
What are the limitations of the exam?
Because bone weakens sound wave, ultrasound cannot be used to examine bones surrounding your abdomen, such as your ribs. Also, because sound is weakened as it passes through layers of tissue, results from patients who are overweight are not of the same quality as those who are thin. In addition, ultrasound cannot obtain images through gas. Thus, bowel gas may limit visualization of some structures of interest. The ultrasound exam quality also depends on the examiner’s experience and the type of equipment used.