What is a chest X-ray?

A chest X-ray is a picture of your child’s chest showing the heart and lungs. The picture is taken using a low dose of radiation.

Why are chest X-rays done?

An X-ray can determine whether a child’s heart or lungs look normal. A chest X-ray can be useful in diagnosing:

  • An enlarged heart
  • Excess fluid around the heart
  • Excess fluid in the lungs
  • Lung problems such as pneumonia, lung cancer, tuberculosis or other lung diseases

Chest X-rays may also be used to check the position of devices such as a pacemaker, defibrillator or a catheter.

How do chest X-rays work?

An X-ray machine emits very tiny particles called photons that pass through the body and are picked up by a sensitive film or imaging plate. Radiation exposure is kept at the lowest dose possible while still making the picture clear. Structures that are dense, like bones, will block most of the photons and appear white on the developed film. Tissue, such as muscle, blood, skin and fat, appears darker.

Smaller bodies often need less radiation to get a good image. The dose of radiation varies with each patient and type of exam. Our team uses age and weight to determine dosage. The radiation doses given at Seattle Children’s are consistently lower than the guidelines recommended by the American College of Radiology. (For more information, read our radiation exposure handout [PDF].)

What happens during a chest X-ray?

You and your child will go to our Radiology Department. Your child will be dressed in a gown. When appropriate, your child will be asked to stand or sit in front of the machine and hold their breath when the X-ray is taken.

The radiology staff at Seattle Children’s has been trained to minimize stress before, during and after testing through the use of distraction. They will use developmentally appropriate techniques to keep your child calm during the X-ray. Two X-ray views are usually taken: one from the front and one from the side.

Having an X-ray is as painless as taking a picture. It will not poke or hurt your child.

How long does a chest X-ray take?

A chest X-ray takes about 5 minutes. The results will need to be read by a radiologist. A radiologist is the doctor who interprets the medical images and works with your child’s heart doctor (cardiologist).

Contact Us

Contact the Heart Center at 206-987-2015 for a cardiac referral, a second opinion or more information.