American Registry of Radiologic Technologists (ARRT) Practice Exam

The quality of the x-rays produced at the anode is primarily controlled by?

1. mAs

2. kVp

3. SID

4. Exposure time

The correct answer is: kVp

The quality of the x-rays produced at the anode is primarily controlled by kilovoltage peak (kVp). kVp determines the overall energy and penetrating power of the x-rays generated during the exposure. Higher kVp settings result in x-rays with greater energy, which can penetrate denser tissues and produce higher quality images. This is crucial for differentiating between various tissue types in radiography, as it affects the contrast and detail visible in the final image. In contrast, milliampere-seconds (mAs) primarily influence the quantity of x-rays produced, meaning it adjusts the amount of exposure and impacts image density but does not change the inherent quality of the x-rays. Source-to-image distance (SID) and exposure time also have their roles in establishing image characteristics, but they do not have the same direct impact on the quality of the x-ray beam as kVp does. Therefore, kVp is the key factor that controls the quality of x-rays at the anode.