X rays are a type of radiation used in imaging andtherapy that uses short wavelength energy beams capable of penetrating most substances except heavy metals.
Diagnostic x rays are some of the most powerful medical imaging tools available. Other imaging techniques that do not use x rays include magnetic resonance imaging (MRI), ultrasonography, and radionucleotide imaging. Based on the symptoms presented by the patient, the physician can request specific x rays (such as chest x rays) that help diagnose many types of cancers, including sarcomas, lymphomas, and lung cancers. X rays allow the physician to visualize certain internal body conditions with little or no invasive procedures. Conditions may be visualized on photographic film, or for more complex and detailed information, computed tomography (CT scan), fluroscopy, or angiography might be used.
Before consenting to any x-ray procedure, the patient should consider the impact of existing medical conditions or medications. Sensitivities to contrast dyes may produce allergic reactions. Pregnant women or those who suspect they might be pregnant should consult a physician prior to x-ray treatments to avoid injury to the fetus. Nursing mothers may be required to store enough milk to last for 48 hours following certain procedures. Patient age should always be taken into consideration when choosing the type and intensity of x ray. Patients should be aware that some prescribed cancer medications act as radiosensitizers and amplify the effect of x rays. Any patient with a suppressed immune system or diabetes may require special x-ray procedures.
X-ray procedures are administered in a hospital orclinical setting. Most procedures may be conducted on an outpatient basis. The time required for the procedure may vary from a few minutes to more than an hour. There is little or no discomfort associated with diagnostic x rays. The general procedure for diagnostic x rays include:
- proper positioning and shielding of the patient
- administering contrast dyes, if necessary
- administering radiation
- review of the films by a technician to insure proper imaging
- Scheduling a time to review the films with the radiolo-gist. However, if fluoroscopy or angiography is used, the procedure is dynamic (in motion), and the radiolo-gist is present during the x ray administration.
- dismissal of the patient
Diagnostic x rays require little preparation. The patient may be required to abstain from food and liquids for a certain period prior to the x ray. For some x rays, enemas may be necessary or a contrast agent may be administered immediately prior to or during the procedure.
For non-invasive diagnostic x-ray procedures, the patient is dismissed immediately after the films have been reviewed, and little or no aftercare is necessary.
A general rule for x rays suggests that the beneficial effects of x rays far exceed the risks involved. As a result of certified training and strict guideline compliance, risks from technical application are essentially nonexistent. However, for any x-ray procedure, radiation exposure is always a concern, and although uncommon, the risk of infection during invasive techniques can not be discounted.
Diagnostic x rays provide detailed information that the physician can use to determine the best approach to correct or control a medical problem. Normal results would indicate no existing abnormalities.
Abnormal results would indicate irregularities such as a tumor, an enlarged lymph node, or pleural effusion. Although highly unlikely, diagnostic x-ray films can be misread and the wrong diagnosis made.
See Also Barium enema; Bone survey; CT-guided biopsy; Imaging studies; Intravenous urography; Lymphangiography; Nephrostomy; Pain management; Percutaneous transhepatic cholangiography; Radiation therapy; Stereotactic needle biopsy; Upper GI series
Brant, William E., and Clyde A. Helms, ed. Fundamentals of Diagnostic Radiology. Second Edition. Baltimore:Williams & Wilkins, 1999.
Cope, Constantine, Dana R. Burke, and Steven Meranze, eds. Atlas of Interventional Radiology. New York: Gower Medical Publishing, 1990.
Henchke, Claudia, et al. "Early Lung Cancer Action Project:Overall Design and Findings from Baseline Screening."Lancet 354 (July 1999): 99-105.
Harrison, Pam. Lung Cancer Detected Earlier with CT Scan than with X ray. 2000 Reuters Ltd. 29 March 2001. 28June 2001 <http://www.respiratorycare.medscape.com>
Marchant, Joan. "Pixels Join Cancer Fight." The Guardian. Dec. 1999. 21 April 2001. 28 June 2001 <http://www.guardianunlimited.co.uk>
"CT Screening Detects Majority of Lung Cancer Cases Missedby X ray." RSNA Meeting. Dec., 1998. 29 March 2001. 28June 2001 <http://www.pslgroup.com>
Jane Taylor-Jones, M.S.
—A radiographic technique in which an opaque contrast material is injected into a blood vessel for the purpose of identifying its anatomy on x ray.
Computed tomography (CT)
—A special radiographic technique that uses a computer to convert multiple x-ray images into a two dimensional cross-sectional image.
—A radiopaque dye that allows enhancement of the anatomy demonstrable with conventional x ray.
—X-ray imaging of moving anatomic structures.
—The accumulation of fluid in the pleural space, the region between the outer surface of each lung.
—A physician specially trained in the use of x-rays for diagnostic and therapy purposes.
QUESTIONS TO ASK THE DOCTOR
- What type of x-ray procedure is best to diagnosis my condition?
- Will the procedure or treatment hurt?
- How long will it take each time and how many treatments are required?
- What are my chances for a complete recovery?
- Are these procedures covered by insurance?