Question

Anatomy absorbs x-rays based on the density of the structure (subject thickness). Consider your understanding of how black, grey, clear and white tones (radiolucent and radiopaque) are created.

Why do some anatomical structures appear black, and others clear or white? Why do some structures allow more x-rays to pass through and energize the film crystals, while other structures do not?

Please use your own words and describe your answer in less than a paragraph in length.

Answer 1

An x-ray machine will send individual x-ray particles through the body.

• 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.

Some structures allow more x-rays to pass through because Different parts of the body absorb X-rays in varying degrees. Dense bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more of the x-rays to pass through them.