CAMRT Radiography Practice Exam

What is meant by the term "attenuation" in radiography?

1. Loss of image quality

2. Energy lost while travelling through a medium

3. Increase in exposure levels

4. Improvement in image contrast

The correct answer is: Energy lost while travelling through a medium

Attenuation in radiography refers to the reduction of the intensity of radiation as it passes through a material. More specifically, it involves the loss of energy that occurs when X-rays or other electromagnetic waves interact with matter, such as human tissue or other substances. This loss of energy can result from scattering and absorption processes. In a clinical context, understanding attenuation is crucial for radiographers because it directly impacts image quality and contrast. Different tissues in the body will attenuate radiation differently based on their density and atomic composition. For example, bones will attenuate X-rays significantly more than soft tissue, which is why they appear lighter on radiographic images. This differential attenuation allows for the visualization of various structures within the body. The other options do not accurately capture the essence of attenuation. While loss of image quality can result from excessive attenuation, it is not the definition of the term. An increase in exposure levels and improvement in image contrast are also not relevant to the concept of attenuation, which specifically deals with the energy loss as radiation travels through a medium.