Computed Tomography Technologist Practice Exam

A display processor uses window width settings to assign a specific number of Hounsfield Units (HU) to each level of gray in CT imaging. Window width refers to the range of HUs displayed in the image and determines the contrast and brightness of the image. By modifying the window width, the display processor adjusts which HUs are mapped to the grayscale, thereby enhancing the visibility of different tissues or structures depending on their attenuation properties.

In CT imaging, tissues with different densities, such as fat, muscle, and bone, absorb X-rays differently, resulting in varying HUs. The window width setting allows the radiologist or technician to focus on a particular range of HUs relevant to the area of interest, improving diagnostic accuracy.

Other options, such as exposure time, detector calibration, and the patient's physical condition, while essential for the overall quality of the CT scan, do not directly influence the assignment of HUs to grayscale levels in the manner that window width settings do.