MedlinePlus Medical Encyclopedia: X-ray

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X-ray

X-rays are a form of electromagnetic radiation, just like visible light. Structures that are dense (such as bone) will block most of the x-ray particles, and will appear white. Metal and contrast media (special dye used to highlight areas of the body) will also appear white. Structures containing air will be black and muscle, fat, and fluid will appear as shades of gray.

Update Date: 3/30/2007

Updated by: Jeffrey J. Brown, MD FACR, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO. Review provided by VeriMed Healthcare Network.

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