CAMRT Radiography Practice Exam

Which term describes the range of attenuation values that can be detected in a CT system?

1. Dynamic range

2. Image contrast

3. Spatial resolution

4. Signal to noise ratio

The correct answer is: Dynamic range

The term that describes the range of attenuation values that can be detected in a CT system is dynamic range. In the context of computed tomography (CT), dynamic range refers to the spectrum of different X-ray attenuation values that can be accurately measured and differentiated by the system. This range is crucial for obtaining high-quality images, as it determines the ability of the CT scanner to discern between various tissues with different densities (such as fat, muscle, organs, and pathological areas). Dynamic range is integral to image quality because it affects how the scanner captures the nuances of tissue differences. A wider dynamic range allows for more subtle variations in attenuation to be displayed, which enhances the diagnostic capability of the CT images. In contrast, image contrast typically pertains to the difference in shading between various structures within the image rather than the detection capabilities of the system itself. Spatial resolution refers to the ability of the system to distinguish small details in the image, while signal to noise ratio relates to the level of detail versus the background noise in the images rather than the range of attenuation values detectable by the system.