Radiography is commonly known as X-ray. The technique was discovered more than a century ago, and is now the most frequently used method of medical imaging.
X-rays are a type of radiation and create no sensation when they pass through the body. In fact, the X-ray techniques used today allow for only a fraction of the radiation dose that was required in the early days of its use.
When passed through human tissue, some of the X-rays are absorbed by the body. Once their energy is absorbed, no residual radiation remains—your body does not become “radioactive” from having an X-ray exam.
The amount of X-rays absorbed depends on the density of the tissue; because bones are hard, they absorb more X-rays, leaving fewer to strike and expose the plate underneath. Bones appear white on an X-ray image and air, such as in the lungs or bowel, appear black. Organs, muscles and other tissues appear as varying shades of gray.
Most X-ray exams require two or more views to be taken. Examination of some structures requires multiple images from different angles.
With the advancements in technology came the ability to make images digital. The images that are taken are on a plate that is read by a laser and imported into a computer. The images can then be networked in a digital format called DICOM (Digital Imaging and Communications in Medicine). All images are stored and archived according to state and federal record keeping regulations
Radiography is a highly regulated medical specialty. All technologists who perform radiology exams have undergone at least two years of special training, are licensed in the state of California, and registered with ARRT (American Registry of Radiologic Technologist). They must continue to take courses to renew their licenses every two years.