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Last Updated: 12/22/16

X-Ray Imaging

X-ray imaging is perhaps the most familiar type of imaging. Most adults have had a chest X-ray to look for an infection or maybe just as part of an employment health check. Some people have had X-rays obtained of a hand or a foot looking for a fracture or metallic splinter. Images produced by X-rays are due to the different absorption rates of different tissues. Calcium in bones absorbs X-rays the most, so bones look white on a film recording of the X-ray image, called a radiograph. Fat and other soft tissues absorb less, and look gray. Air absorbs least, so lungs look black on a radiograph. The most familiar use of X-rays is checking for broken bones. We can also use X-rays to look for cancer. X-rays are also used in cancer diagnosis. For example, chest radiographs and mammograms are often used for early cancer detection or to see if cancer has spread to the lungs or other areas in the chest. Mammograms use X-rays to look for tumors or suspicious areas in the breasts.