American Registry of Radiologic Technologists (ARRT) Practice Exam

The choice of the highest kilovoltage peak (kVp) combined with the lowest mass is effective in delivering the least amount of exposure, primarily due to the relationship between kVp, mass, and the quality of the x-ray beam.

Higher kVp values result in greater energy x-rays being produced, which leads to increased penetrating power. This increased penetration means that the x-rays can more effectively pass through the body without requiring higher levels of mass or exposure time. When combined with the lower mass (or mAs—milliamperes multiplied by time), the overall radiation dose to the patient is reduced.

In radiography, a higher kVp is beneficial not only for penetrating capability but also for lowering patient dose, since lower mAs values correlate to a lower quantity of x-ray photons generated. Therefore, using maximum potential kVp while minimizing mass enables a more efficient imaging process that ultimately protects the patient from unnecessary radiation exposure.

The other combinations focus on different balances of kVp and mass, which typically do not provide the same advantage in reducing exposure while also maintaining image quality. Lower kVp with high mass could lead to increased patient exposure due to higher overall photon output with less penetrating ability. Similarly, medium kVp and medium mass or