A chest ultrasound is an imaging test. It uses sound waves to look at the structures and organs in your chest. It can help your doctor see how well your lungs and heart are working.

A chest ultrasound can look at these areas:

• Lungs
• Heart
• Food pipe (esophagus)
• Mid-chest area (mediastinum)
• The space between the lungs and chest wall (pleural space)
• Other structures in the chest

Your doctor may also use ultrasound to see how blood flows through the organs in your chest.

The doctor uses a small, handheld device (probe or transducer) to make the images of your chest. The transducer sends out sound waves that bounce off your organs and other structures. 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 organs.

Your doctor can add another device called a Doppler probe to the transducer. This probe lets your doctor hear the sound waves the transducer sends out. They can hear how fast blood is flowing through a blood vessel. The doctor can also hear in which direction it is flowing. No sound or a faint sound may mean that you have a blockage in the flow.

Ultrasound is safe to have during pregnancy. It does not use radiation. It does not use dye, so it is safe for people who are allergic to contrast dye.

You may need a chest ultrasound if your doctor thinks you have extra fluid in your chest. This is especially true if the amount of fluid is small.

A chest ultrasound can also be used to:

• Look at your heart and its valves—a test called an echocardiogram.
• Guide a needle to remove fluids from the chest (thoracentesis).
• See how well your diaphragm moves.
• See if you have fluid building up in the lung.
• See if you have areas of the lung that are more dense than others, which will help find out if you have an infection, lung collapse, or other condition.

Chest ultrasound may be used along with other types of imaging tests to diagnose chest conditions. These other tests include CT scans, X-rays, and MRI.

Your doctor may have other reasons to advise a chest ultrasound.

A chest ultrasound has no risk from radiation. Most people have no discomfort from the transducer moving across the skin.

Certain things can make a chest ultrasound less accurate, such as:

• Severe obesity

• Your doctor will explain the test to you. Ask them any questions you have about the test.
• You may be asked to sign a consent form that gives permission to do the test. Read the form carefully and ask questions if anything is not clear.
• You usually do not need to stop eating or drinking before the test. Also, you likely will not need medicine to help you relax (sedation).
• Tell your doctor if you are pregnant or think you may be pregnant.
• Wear clothing that you can easily take off. Or wear clothing that lets the radiologist reach your chest. The gel put on your skin during the test does not stain clothing. But you may want to wear older clothing. The gel may not be completely removed from your skin afterward.
• Follow any other instructions your doctor gives you to get ready.

You may have a chest ultrasound as an outpatient. This means you go home the same day. Or it may be done as part of your stay in a hospital. The way the test is done may vary. It will depend on your condition and your doctor's practices.

Generally, a chest ultrasound follows this process:

1. You will be asked to remove any clothing, jewelry, or other objects that may get in the way of the scan.
2. If you are asked to remove clothing, you will be given a gown to wear.
3. You will lie on the exam table, either on your back or side. Or you will sit with your arms raised and your hands clasped behind your neck. Your position on the table depends on the area that the radiologist needs to look at.
4. The technologist will put a clear gel on your 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. You may be asked to shift positions so that the technologist can see other areas. You also may be asked to cough or sniff during the test. This will let the technologist see how certain structures in your chest move.
7. If blood flow is being looked at, you may hear a "whoosh, whoosh" sound when the Doppler probe is used.
8. Once the test is done, the technologist will wipe off the gel.

A chest ultrasound is not painful. But you may have some discomfort from having to stay still during the test. The gel will also feel cool and wet. The technologist will use all possible comfort measures. They will do the scan as quickly as possible to minimize any discomfort.

You don't need any special care after a chest ultrasound. Your doctor may give you other instructions depending on your situation.

Before you agree to the test or procedure, make sure you know:

• The name of the test or procedure
• The reason you are having the test or procedure
• What results to expect and what they mean
• The risks and benefits of the test or procedure
• What the possible side effects or complications are
• When and where you are to have the test or procedure
• Who will do the test or procedure and what that person's qualifications are
• What would happen if you did not have the test or procedure
• Any alternative tests or procedures to think about
• When and how you will get the results
• Who to call after the test or procedure if you have questions or problems
• How much you will have to pay for the test or procedure