RADIOGRAPHY
DEFINITION
A technique for generating and recording an x-ray pattern for the purpose of providing the user with a static image(s) after termination of the exposure.
TYPES
(fluoroscopic) Angiography
Dual energy X-Ray absobtiometry
HOW IT WORKS
To produce an X-ray picture, an X-ray machine produces a very concentrated beam of electrons known as X-ray photons. This beam travels through the air, comes into contact with our body tissues, and produces an image on a metal film.
Soft tissue, such as skin and organs, cannot absorb the high-energy rays, and the beam passes through them. Dense materials inside our bodies, like bones, absorb the radiation.
Much like camera film, the X-ray film develops depending on which areas were exposed to the X-rays. Black areas on an X-ray represent areas where the X-rays have passed through soft tissues. White areas show where denser tissues, such as bones, have absorbed the X-rays.
WHEN ITS USED
Radiography is used in many types of examinations and procedures where a record of a static image is desired. Some examples include
Dental examination
Verification of correct placement of surgical markers prior to invasive procedures
Mammography
Orthopedic evaluations
Spot film or static recording during fluoroscopy
Chiropractic examinations
RISKS AND BENEFITS
The radiation dose the patient receives varies depending on the individual procedure, but is generally less than that received during fluoroscopy and computed tomography procedures.
The major risks associated with radiography are the small possibilities of
developing a radiation-induced cancer or cataracts some time later in life, and
causing a disturbance in the growth or development of an embryo or fetus (teratogenic defect) when performed on a pregnant patient or one of childbearing age.
When an individual has a medical need, the benefit of radiography far exceeds the small cancer risk associated with the procedure. Even when radiography is medically necessary, it should use the lowest possible exposure and the minimum number of images. In most cases many of the possible risks can be reduced or eliminated with proper shielding.
PROTECTIVE MEASURES
Lead is the most common shield against X-rays because of its high density (11340 kg/m3), stopping power, ease of installation and low cost.
https://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/MedicalX-Rays/ucm175028.htm