X-ray, also known as radiography, is the oldest and most frequently utilized form of diagnostic imaging. Discovered more than a century ago, X-rays can produce images of the human body on film, or more recently, the images can be acquired digitally and projected on a computer screen to be visualized.
X-ray imaging is a fast and efficient diagnostic method that aids physicians in viewing internal bodily structures, thereby enabling them to more definitely diagnose disease and injury. X-rays are most frequently utilized to evaluate the chest (lungs and heart), the skeletal system (bones of the arms, legs, hands and feet as well as the cervical and lumbar spine), and abdomen (to assess gas patterns and internal organs). Many other specific areas of the body can also be evaluated with X-rays. Furthermore, images are frequently obtained in more than one position or view to enhance visibility and diagnostic capability.
X-ray technology involves passing a radiant beam through a part of the body to ultimately produce an image of internal structures. As X-rays penetrate the body, they are absorbed in varying amounts by different tissues. For example, bones absorb much of the radiation, soft tissues absorb less, and lung tissue absorbs very little. The X-ray beams that are not absorbed by body tissues penetrate through and are captured by a sensor—either film or digital. The more X-rays that penetrate the body and reach the sensor, the darker the image will appear. Likewise, the fewer X-rays that penetrate the body and reach the sensor, the lighter the image will appear. Since the lungs do not absorb much of the penetrating X-rays, they look dark or black on the resulting image. On the other hand, since bone absorbs much of the penetrating X-rays, it looks light or white on the resulting image. Soft tissues that absorb a moderate amount of penetrating X-rays consequently look grayish on the resulting image. By using X-ray technology, radiologists can view internal structures with respect to each other as varying shades of dark to light based on their density.
Depending on the part of the body being examined, the patient may be asked to remove clothing and metal objects and wear a loose-fitting hospital gown. An X-ray technologist will position the patient appropriately, based on the body part being examined. The technologist will then ask the patient to hold very still without breathing for a few seconds while they activate the radiographic equipment and send the beam of X-rays through the intended body part. It is important to hold still without breathing for the few seconds while the image is obtained so motion will not degrade the quality of the image. The technologist will then likely reposition the patient for another view, and the process will be repeated. Besides remaining still in a potentially awkward position for a brief period of time, the patient should not experience any discomfort or pain during the procedure.
The amount of radiation used with conventional X-rays is extremely low. Lahey Hospital & Medical Center uses modern, state-of-the-art equipment with tightly controlled X-ray beams that have significant filtration and dose control methods. The result is that stray or scattered radiation is minimized, ensuring that parts of the body not being examined receive very little exposure. However, if there is any possibility that the patient may be pregnant, the doctor or the X-ray technologist should be informed ahead of time.
X-rays can be stored as hard copy film that is filed, or as filmless digital images—now a more common method— that are archived electronically on our PACS system (picture archiving and communication system). Hard copy film can be converted to digital images as needed. These digital images can also be transferred for convenient transport onto CD-ROM. If a patient develops an illness or injury, these stored images are frequently used for comparison. Comparison of current images to older ones is often instrumental in the radiologist’s determination as to whether a finding is clinically important or not.
Information on how to obtain your X-ray images