An x-ray is a painless test in which an image is created of part of the body by using low doses of electromagnetic radiation that are reflected on film paper or fluorescent screens. X-rays can be used to diagnose a wide range of conditions, from bronchitis to a broken arm. When viewing x-ray images of the heart, physicians can evaluate the size, activity and function of the heart’s chambers and vessels, as well as surrounding organs such as the lungs. Depending upon a physician’s evaluation of an x-ray image, further tests may be ordered.

X-ray images may be taken with no preparation, or in some cases, the physician might use a special dye called a contrast medium. This dye appears on the x-ray image and is helpful to highlight certain structures and conditions within the body. If contrast medium is going to be used, changes may be made in the patient’s diet or medication schedule. Women who are pregnant or think they might be are urged to either avoid x-rays or to wear a protective lead apron over their abdominal area.

An x-ray is a painless test in which an image is created of part of the body by using low doses of radiation reflected on film paper or fluorescent screens. These images, also known as a radiograph or roentgenogram, are used to diagnose and monitor the treatment of various diseases. They are noninvasive, relatively inexpensive and fast.

X-rays of the heart and its various structures are referred to as chest x-rays. They can be used for any of the following:

In addition to the standard x-ray, there are a number of tests used by cardiologists that involve the use of x-rays. These tests include:

• Fluoroscopy. A special x-ray technique in which a real-time image is projected on a video monitor. This is frequently used during catheter-based treatments.
  
  
• Computed tomography scan (CAT scan). A test that uses a rotating x-ray tube to generate multiple images from all 360 degrees. The images are then collated by a computer to produce three-dimensional images of the body tissues.
  
  
• Coronary angiogram. A special x-ray of the coronary arteries that is usually done as part of a cardiac catheterization.

X-ray technology is sometimes used to treat cancer and other conditions that involve rapid and harmful tissue growth. High doses of radiation are meticulously calculated to destroy cancer cells and tumors in specific parts of the body while sparing the healthy normal cells. This is known as radiation therapy and is not considered an x-ray.

Imagine that an individual is  standing between a wall and a window through which sunlight is streaming. Because sunlight cannot pass through the solid barrier created by your body, a shadow will be cast against the wall. X-rays have been likened to rays of sunlight because they cannot pass through solid barriers such as bones, organs or tumors. As a result, these barriers will appear on the special x-ray film in white, whereas less dense barriers, such as organs, muscle and fat, will appear in varying shades of gray. Bones, which are dense and calcium rich, will appear the whitest of all internal structures. Any solid objects, such as metal, will appear as bright white.

Additional techniques may be necessary to get a clear view of softer tissues, hollow areas or fluid-filled body parts. For example, a physician may administer a special dye known as a contrast medium to produce sharper contrasts in light and dark areas on the x-ray. These contrasts give the physician a clearer image of areas such as the urinary tract, the spinal cord, blood vessels and the gallbladder.

X-rays were discovered almost by accident in the 1890s by a German scientist named Wilhelm Conrad Roentgen. Because no one understood the rays that were at work in forming these images, the rays were initially called x-rays. Much more is now known about this form of radiation.

Today, the special silver–coated x-ray film is contained in a flat cassette that is placed on the far side of the patient. The area to be examined is placed between the metal film cassette and the x-ray tube, which is surrounded in lead casing except for a small opening through which the rays are beamed. Within the x-ray tube, a beam of electrons is fired into a target made of a chemical element known as tungsten, emitting photons that travel straight and outward from a point on the target to the area being x-rayed. The resulting images are recorded on either film or a fluorescent screen.

Some of these photons pass directly through the body, while tissues in the body absorb the rest. The energy contained in the photons may cause some cell damage. Most of this cell damage is repaired quickly, but some may be permanent. Considering the low doses of radiation in modern x-ray tests, most physicians believe the benefits of x-rays outweigh the very small risk associated with them. However, young children, including developing fetuses, are more sensitive, and women should advise their physicians if they are pregnant.

In general, no special preparation is needed before an x-ray is taken, unless a special dye called a contrast medium is going to be used. X-rays may be taken in a clinic, physician’s office or hospital. If a dye will be used, then patients may be asked not to eat or drink after midnight before the test, and the physician may make minor changes in how the patient takes medication. The physician will also ask about the patient’s history of allergies to screen for a potential allergic reaction to the dye.

A radiology technician or specially trained nurse generally takes x-ray films. At the time of the test, he or she will ask the patient to remove any objects that may interfere with the x-ray imaging (e.g., clothing, jewelry, watches and/or dentures). Patients should inform the examiner if they have had an x-ray using a contrast dye or barium in the past few days. Patient should also make sure the examiner is aware of all medications that have been taken recently, including over-the-counter medications.

Female patients should be sure to inform the examiner if they are or may be pregnant, or if they currently have an IUD (a form of birth control) implanted. Although today’s modern equipment and technology uses only minimal radiation when taking an x-ray, pregnant women are urged to either avoid x-rays or to wear a lead apron over the abdominal area if testing is necessary. X-rays cannot pass through the lead in the apron, offering protection for the fetus. Sometimes women of childbearing age prefer to wear a lead apron even if they are not pregnant to protect their reproductive organs. Both male and female examiners may also wear these lead aprons themselves to protect their reproductive organs against any cumulative effects of x-rays.

Depending on the area of the body that needs to be x-rayed, the patient will be asked to position his or her body accordingly. An x-ray of an arm may only require the patient to put his or her arm in a certain position on a table, whereas a chest x-ray will require the patient to lie on the table or stand in front of the machine and hold their breath.

The technician who operates the x-ray machine is a radiographer, and he or she will tell the patient when to move, shift, take a deep breath or perform other actions that may be necessary to take a clear image.

The technician will step out of the room and activate the x-ray from behind a protective leaded curtain or other barrier. To perform a chest x-ray, two views will usually be taken:

Patients can resume normal activities immediately following the x-ray(s). Either a radiologist or the patient’s physician will interpret the findings and review them with the patient. The physician will review the results with the patient either that same day or at a follow-up visit. Abnormal cardiovascular findings that may be detected by a chest x-ray include:

Depending on what is found by the x-rays, the physician may recommend either additional tests or design a treatment plan for the patient.

Additional tests may be necessary if the x-rays do not provide enough information on the tissues or structures being studied. These tests could include:

• CAT scan of the chest
• Magnetic resonance imaging (MRI)
• Biopsy

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to the x-ray:

1. Why are you ordering an x-ray for me?
   
   
2. What type of x-ray will I receive?
   
   
3. What conditions do you hope to detect with an x-ray?
   
   
4. Will a contrast medium be used?
   
   
5. Do I need any special preparations prior to the x-ray?
   
   
6. Where should I go to have the x-ray?
   
   
7. What type of test results should I consider normal or abnormal?
   
   
8. When and from whom will I receive the results of the x-ray?
   
   
9. How long will the x-ray take?
   
   
10. Can I still have the test if I am pregnant? If not, is there another test I should have instead?
    
    
11. Will you require any other tests to make a diagnosis?
    
    
12. Will I need to follow-up appointment after the test has taken place?