CAMRT Radiography Practice Exam

If lung tissue is the primary focus for a CT exam, which window level setting is most appropriate?

1. 50

2. 400

3. 0 or the level of water

4. -600

The correct answer is: -600

When performing a CT exam focused on lung tissue, the appropriate window level setting is typically a negative value, such as -600. This is because lung tissue's density is quite low compared to other tissues, mainly consisting of air-filled spaces. Setting the window level at -600 enhances the contrast of the lung tissue against the surrounding structures, allowing for clearer imaging of any abnormalities, such as nodules or signs of pathology. The negative window level effectively allows the radiologist to visualize the subtle variations in lung density, improving diagnostic capabilities. In contrast, setting the window level at higher values, such as 50, 400, or even at the level of water (0), would not enhance visualization of the lung tissue as effectively, as these levels cater more to denser materials and would create a loss of detail in the lungs. Therefore, a window level setting at -600 is specifically tailored to accentuate the features of lung tissue in CT imaging.