American Registry of Radiologic Technologists (ARRT) Practice Exam

In radiography, kilovolt peak (KVP) plays a critical role in controlling image contrast. KVP is the peak voltage applied to the x-ray tube, and it affects the energy of the x-rays produced. When the KVP is increased, the x-ray beam becomes more penetrating, allowing it to pass through denser tissues with greater ease. This results in a wider range of tissue density being captured on the film or detector, which enhances the differences between various tissues, therefore improving the contrast of the image.

High KVP settings typically produce images that have lower contrast because the greater energy x-rays can penetrate more tissues uniformly. Conversely, lower KVP settings yield higher contrast images, as they are less penetrating and therefore more influenced by the differences in tissue densities. Understanding the relationship between KVP and image contrast is essential for radiologic technologists to produce diagnostic-quality images tailored to the specific needs of the examination.

The other options relate to different aspects of radiography that are influenced by parameters other than KVP. For example, exposure time is primarily controlled by the milliamperes (mA) settings and affects the overall exposure received by the film or detector; film speed refers to the sensitivity of the film to radiation, which