Bone x rays are a diagnostic imaging test in which ionizing radiation passing through the bones enables an image to be produced on film.
Bone x rays are ordered to detect bone disease or injury, such as in the case of 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 such diseases as arthritis.
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 doctor reads the developed x ray on a wall-mounted light box or on a computer monitor.
Digital x rays are a new type of exam in which conventional equipment is used to take the x-ray picture, 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 that is connected to a computer network. The radiologist reads the x ray from there. An electronic report can then be sent to the patient's doctor. Electronic reports can also be generated with non-digital x-ray exams.
X rays can detect problems with bones that result from injury or disease caused by malfunction in the patient's bone chemistry. Bone injuries, especially broken bones (fractures), are common and can be accurately diagnosed by evaluation of bone x rays. X rays are especially helpful in diagnosing simple and incomplete fractures, which cannot be detected during a physical examination . X rays can also be used to check for bone position and alignment in a fracture. Some bone diseases can be definitively diagnosed with bone x rays, while others require additional, more sophisticated imaging tests.
Osteoporosis, a common bone disease, can be detected in bone x rays, but other tests, such as bone densitometry, may need to be ordered to determine the extent of the disease. In some cases, a bone biopsy (microscopic analysis of a small amount of tissue) is also done. For arthritis, a common ailment, x rays of the bone are occasionally used in conjunction with blood tests. In bone tumors, bone x rays can be helpful, but they may not be definitive when used alone.
Bone x rays are taken by a technologist or radiologist and interpreted by a radiologist. They are taken in a doctor's office, in a hospital, or in an outpatient clinic. Bone x rays generally take less than 10 minutes to complete. There is no pain or discomfort associated with the test, but some people find it difficult to remain still throughout the procedure.
During the test, the patient lies on a table. The technician taking the x ray checks the patient's position and places the x-ray machine over the part of the body being scanned. After asking the patient to remain still, the technician 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 part of the body being x rayed. If appropriate, a lead shield is placed over another part of the body to minimize exposure to the radiation that is being used.
The patient can immediately resume normal activities once the technician has checked that the x-rays have processed well and that none need to be repeated. This takes just a few minutes.
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 to be exposed to large amounts of radiation, genetic alterations could occur in the developing fetus. 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 that indicate the presence of bone injury or disease differ in appearance, according to the nature of the injury or disease. For example, fractures show up as clear breaks in the bones, while osteoporotic bone has the same shape as normal bone on an x ray, but is less dense.
A Manual of Laboratory and Diagnostic Tests. 5th ed. Ed. Francis Fishback. Philadelphia: Lippincott, 1996.
"Tumors and Tumor-Like Lesions of the Bone." In Current Medical Diagnosis and Treatment, 1996. 35th ed. Ed. Stephen McPhee, et al. Stamford: Appleton & Lange, 1995.
Lori De Milto Lee A. Shratter, MD