Bone
X-ray
This procedure is reviewed by a physician with expertise in the area presented and is
further reviewed by committees from the American College of Radiology (ACR) and the
Radiological Society of North America (RSNA), comprising physicians with expertise in
several radiologic areas.
What is
Bone
X-ray
Radiography, known to most people as x-ray, is the oldest and most frequently used form of
medical imaging. For nearly a century, diagnostic images have been created by passing
small, highly controlled amounts of radiation through the human body, capturing the
resulting shadows and reflections on a photographic plate.
X-ray imaging is the fastest and easiest way for a physician to view and assess broken
bones, cracked skull and injured backbone. At least two films are taken of a bone, and
often three films if the problem is around a joint (knee, elbow, or wrist). X-rays also
play a key role in orthopedic surgery and the treatment of sports injuries. X-ray is
useful in detecting more advanced forms of cancer in bones. Very early cancer findings
require other methods.
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.
What are some common uses of a
Bone X-ray?
Probably the most common use of bone X-ray is to assist the physician in identifying
and treating fractures. X-ray images of the skull, spine, joints, and extremities are
performed every minute of every day in hospital emergency rooms, sports medicine centers,
orthopedic clinics, and physician offices. Images of the injury can show even very fine
hairline fractures or chips, while images produced after treatment ensure that a fracture
has been properly aligned and stabilized for healing. Bone x-rays are an essential tool in
orthopedic surgery, such as spinal repair, joint replacements, or fracture reductions.
X-ray images can be used to diagnose and monitor the progression of degenerative diseases
such as arthritis. They also play an important role in the detection and diagnosis of
cancer, although usually computed tomography (CT) or MRI is better at defining the extent
and the nature of a suspected cancer. On regular x-rays severe osteoporosis is visible,
but bone density determination detects early loss of bone density. Bone density
determination is usually done on special equipment.
How should I prepare for a bone X-ray?
There is no special preparation required for most bone X-ray. Once you arrive, you
may be asked to change into a gown before your examination. You will also be asked to
remove jewelry, eyeglasses, and any metal objects that could obscure the images, since
those show up on x-rays and may block the bones. Women should always inform their doctor
or x-ray technologist if there is any possibility that they are pregnant.
What does the equipment look like?
Radiography equipment consists of a large, flat table with a drawer that holds an x-ray
film cassette into which a film is placed. Suspended above the table, is an apparatus that
holds the x-ray tube that can be moved over the body to direct the x-ray.
Examples of the radiography equipment that may be used are shown at the top of this page.
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 part of the anatomy. Ribs, for example, will absorb much of
the radiation and, therefore, appear white or light gray on the image. Soft tissue such as
the liver or lungs will appear darker because it absorbs less radiation. Broken bones or
malignancies in the bone can usually be detected with radiography.
The exposed film is either placed in a developing machine, producing images much like the
negatives from a 35 mm camera, or images are digitally stored on
computer.
How is the procedure performed?
The technologist positions the patient on the examination table, places a flat
holder (cassette) under the table in the area of the body to be imaged. Sandbags or
pillows may help the patient hold the proper position. Then the technologist goes to a
small adjacent room and asks the patient to hold very still without breathing for a few
seconds. The radiographic equipment is activated, sending a beam of x-rays through the
body to expose the film. The technologist then repositions the patient for another view,
and the process is repeated. Usually, a bone exam takes less than 15 minutes.
When the x-rays are completed you will be asked to wait until the technologist and
radiologist examine the images to determine if more are needed.
What will I experience during the procedure?
In most cases, x-ray imaging is painless and the only discomfort results from the coldness
of the plate. Sometimes, to get a clear image of an injury such as a possible fracture,
you may be asked to hold an uncomfortable position for a short time. Any movement could
blur the image and make it necessary to repeat the procedure to get a useful, clear
picture.
Who interprets the results and how do I get them?
A radiologist, who is a physician experienced in bone x-ray and other radiology
examinations, will analyze the images and send a signed report with his or her
interpretation to the patient’s personal physician. The personal physician's office
will inform the patient on how to obtain their results. New technology also allows for
distribution of diagnostic reports and referral images over the Internet at some
facilities.
What are the benefits vs. risks of a
Bone X-ray?
Benefits
X-ray imaging is useful to diagnose bone injury and disease, such as fractures, bone
infections, arthritis, and cancer.
Because x-ray imaging is so fast and easy, it is particularly useful in emergency
diagnosis and treatment.
X-ray equipment is relatively inexpensive and widely available in physician offices,
ambulatory care centers, nursing homes, and other locations. So examinations are usually
convenient for both patients and physicians.
Risks
X-rays are a type of invisible electromagnetic radiation and create no sensation when they
pass through the body. Modern x-ray techniques use only a fraction of the x-ray dose
required in the early days of radiology.
Women should always inform their doctor or x-ray technologist if there is any possibility
that they are pregnant.
During a procedure, a patient is exposed to approximately 20 milliroentgens of radiation.
This compares with the 100 milliroentgens of radiation we are all exposed to each year
from sources such as the ultraviolet rays of the sun and the traces of uranium found in
the soil.
Radiation risks are further minimized by:
The use of high-speed x-ray film that requires only very small amounts of radiation to
produce an optimal image.
Technique standards established by national and international guidelines that have been
designed and are continually reviewed by national and international radiology protection
councils.
Modern, state-of-the-art x-ray systems (including mammography systems, angiographic
equipment, labs, and CT scanners) that have very tightly controlled x-ray beams with
significant filtration and x-ray dose control methods. Thus, scatter or stray radiation is
minimized and those parts of a patient’s body not being imaged receive minimal
exposure.
What are the limitations of bone X-ray?
While x-ray images are among the clearest, most detailed views of bone tissue, they may
not provide equally revealing information about involved soft tissues. In the case of a
knee or shoulder injury, for example, an MRI may be more useful in identifying small
ligament tears or other problems. Other imaging modalities, such as bone scans or CT, may
be more effective in diagnosing small tumors in the bone.
If you are looking for a healthcare facility in your region that offers this and other
radiology procedures, the ACR Chapter in your state may be able to assist.
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