Bone x rays are a diagnostic test in which ionizing radiation passing through the bones being examined enables an image to be produced on film.
Bone x rays are ordered to detect disease or injury to the bone such as broken bones, tumors, and other problems. They can determine bone density, texture, erosion, and changes in bone relationships. Bone x rays also evaluate the joints for diseases such as osteoarthritis.
Precautions should be taken to protect patients from unnecessary exposure to radiation. Patients should be shielded with lead aprons as much as possible. Women of childbearing age who could be pregnant should not have x rays of their trunk or pelvic regions. The fetus is especially at risk during the first trimester of pregnancy. Women who are pregnant should not have x rays of their pelvic region, lumbar spine, and abdomen unless absolutely necessary. If other types of x rays are necessary, a lead apron should be used to shield the abdominal and pelvic regions.
X rays are a common diagnostic test in which a form of energy called x-ray radiation penetrates the patient's body. In bone x rays, electrical current passes through an x-ray tube and produces a beam of ionizing radiation that passes through the bone(s) being examined. This produces a picture of the inside of the body on film. The physician reads the developed x ray on a wall-mounted light box.
Digital x rays are a new type of x ray in which conventional equipment is used to take the x ray but the image is produced via computer. In a digital x ray, the image is created on a reusable plate. After being read by a laser reader, the information is sent in digital form to a storage unit connected to a computer network from which the radiologist reads the x ray. An electronic report can then be sent to the patient's physician.
Problems with bones that x rays can detect result from injury or from disease caused by a malfunction in the patient's bone chemistry. Bone injuries, especially broken bones (fractures), are common and can be accurately diagnosed by bone x rays. X rays are especially helpful in diagnosing simple and incomplete fractures which can't be detected during a physical examination. X rays can also be used to check for bone position in a fracture. Some bone diseases can be definitively diagnosed with bone x rays while others require additional tests.
Osteoporosis, a common bone disease, can be detected in bone x rays but other tests are then ordered to determine the extent of the disease. For osteomalacia and rickets, a blood test and x rays of the affected bone are usually definitive; in some cases a bone biopsy (microscopic analysis of a small ammount of tissue) is also done. In a rare bone disease called Paget's disease, x rays may be used in conjunction with bone, blood, and urine tests to make a diagnosis. In another rare bone disease, fibrous dysplasia, bone x rays or a bone biopsy (microscopic analysis of a small amount of tissue) are used to confirm the diagnosis. Bone x rays are definitive in diagnosing osteogenesis imperfecta. For osteomyelitis, bone x rays are used in conjunction with a blood test, bone scan, or needle biopsy to make the diagnosis. For arthritis, x rays of the bone are occasionally used in conjunction with blood tests. In bone tumors, bone x rays are helpful but they may not be definitive.
Bone x rays are performed by a technician or radiologist, and interpreted by a radiologist. They are taken in a physician's office, radiology unit, outpatient clinic, or diagnostic clinic. Bone x rays generally take less than 10 minutes. There is no pain or discomfort associated with the test, but some people find it difficult to remain still. The results are often available in minutes.
During the test, the patient lies on a table. The technician taking the x ray will check the patient's positioning and place the x-ray machine over the part of the body being examined. After asking the patient to remain motionless, he or she steps out of the area and presses a button to take the picture.
The patient is asked to remove clothing, jewelry, and any other metal objects from the area being x rayed. If appropriate, a lead shield will be placed over other body parts to minimize exposure to radiation.
The patient can immediately resume normal activities.
The human body contains some natural radiation and is also exposed to radiation in the environment. There is a slight risk from exposure to radiation during bone x rays, however, the amount of radiation is small and the risk of harm is very low. If reproductive organs are exposed to radiation, genetic alterations may occur. Excessive or repeated doses of radiation can cause changes in other types of body tissue. No radiation remains in the body after the x ray.
Normal bones show no fractures, dislocations, or other abnormalities.
Results which indicate the presence of bone injury or disease differ in appearance according to the nature of the injury/disease. For example, fractures show up as clear breaks in the bones, while osteoporotic bone has the same shape as a normal bone on an x ray but is less dense.
- A disease of the joints that arises from wear and tear, age and less often from inflammation.
- Osteogenesis imperfecta
- Also called brittle bones, this is a condition present at birth in which bones are abnormally fragile, brittle and break easily.
- A disease in which bones gradually soften and bend.
- An infection of the bone marrow and the bone.
- A disease which occurs primarily in post-menopausal women in which the amount of bone is reduced or skeletal tissue wastes away.
- Paget's disease
- A disease, whose cause is unknown, which is generally found in older people. Symptoms include bone pain, bowed legs, curves spine, and broken bones. Another name for this disease is osteitis deformans.
For Your Information
- Fischbach, Frances, ed. "X-ray Studies." In A Manual of Laboratory and Diagnostic Tests. Philadelphia, New York: Lippincott, 1996.
- Tierney, Jr., Lawrence M., Stephen J. McPhee, and Maxine Papadakis, eds. "Tumors and Tumor-Like Lesions of the Bone." In Current Medical Diagnosis and Treatment, 36th ed. Stamford, CT: Appleton & Lange, 1997, 796.
- "FDA Approves Bone Density Measurement Device." Women's Health Weekly, (23 March 1998): 13.
- Tanner, Lisa. "New Radiology Saving Money-And Maybe Lives." Dallas Business Journal, 20 (25-31 July 1997): 23.
- Wu, C. "Nylon May Take X Rays into Digital Age." Science News, 150 (3 August 1996): 70.
- Thriveonline."Bone Fracture," and "Osteporosis: Improved Detection and Treatment." (1998). http://www.thriveonline.com/health/Library (15 April 1998).
Gale Encyclopedia of Medicine. Gale Research, 1999.