X-Ray in Radiology

Radiography, or as it is most commonly known, an x-ray, is the oldest and most frequently used form of medical imaging. Discovered more than a century ago, x-rays can produce diagnostic images of the human body on film or digitally on a computer screen.

X-ray imaging is the fastest and easiest way for a physician to view and assess broken bones, joint or spine injuries, chest and lung, and many other conditions. At least two images (from different angles) are taken and often three images are needed if the problem is around a joint (knee, elbow or wrist). X-rays also play a key role in guiding orthopedic surgery and in the treatment of sports-related injuries. X-ray may uncover more advanced forms of cancer in bones or soft tissue although early screening for cancer findings requires other methods.

To this end radiologists have developed alternative imaging methods that do not rely on radiation, such as ultrasound and magnetic resonance imaging (MRI). However, because x-ray was the first imaging modality, many people (and medical imaging professionals) continue to use the term "radiology" to include all types of imaging. Strictly speaking, though, radiology refers to the use of x-rays.

How should I prepare for the procedure?

This procedure requires no special preparation. Women should always inform their doctor or x-ray technologist if there is any possibility that they are pregnant.

How does the procedure work?

Radiography involves exposing a part of the body to a small dose of radiation to produce an image of the internal organs. When x-rays penetrate the body, they are absorbed in varying amounts by different parts of the anatomy. The ribs and spine, for example, absorb much of the radiation and appear white or light gray on the image. Lung tissue absorbs little radiation and appears dark on the image. Depending upon the type of image-recording medium, chest x-rays can be maintained as hard-copy film for filing or, more commonly, as filmless digital images that are archived electronically. Digital images can also be transferred for storage onto CD-ROM. Stored images may be used to compare with later images if illness develops. Indeed, historical comparison films are often very important in the decision process as to whether a finding is clinically important or not.

How is the procedure performed?

Patients must remove their clothing, including undergarments that may contain metal. Most medical centers will give the patient a loose-fitting gown to wear. Patients will also be asked to remove all metallic jewelry that may interfere with the x-rays. Normally, a frontal or posteroanterior view is obtained, in which the patient stands with the body section pressed to the photographic plate, with hands on hips and elbows pushed in front in a somewhat exaggerated position. The technologist will ask the patient to be still and to take a deep breath and hold it. Breath-holding after a deep breath reduces the possibility of a blurred image and also enhances the quality of the x-ray image, since abnormalities in air-filled lungs are easier to see than in deflated lungs. Next, the technologist walks into a cubicle or small room to activate the radiographic equipment, which sends a beam of x-rays from the x-ray source behind the patient, through the patient's chest, to the recording medium (film or digital cassette). Some equipment is designed to accommodate patients who cannot stand for chest x-rays.

The technologist may need to take additional views to properly see all parts of the chest or may take a side view, or lateral view, of the chest. For a lateral view, the patient stands sideways to the photographic plate with arms elevated, and the process is repeated. Views from other angles may be obtained if the radiologist needs to evaluate additional areas of the chest. Finally, a chest x-ray may be repeated within hours, days or months to evaluate for any changes. These repeated, sequential examinations are called serial chest x-rays.

When the chest x-rays are completed you will be asked to wait until the technologist checks the images for motion and makes sure that the entire chest is included. Ultimately, a radiologist will interpret the chest x-ray images using a lighted view box to review films or a computer and monitor to review digital images.

What will I experience during the x-ray procedure?

This is a painless procedure. The primary discomfort may come from the coldness of the recording plate. Individuals with arthritis or injuries to the chest wall, shoulders or arms may have discomfort trying to maintain position for the chest x-ray. In these circumstances, the technologist will assist you in finding a position that still ensures diagnostic image quality.