American Society of Radiologic Technologist (ASRT) Practice Exam

Which of the following options does NOT help minimize patient exposure?

1. A single-phase generator

2. Added tube filtration

3. Beam restriction

4. Low mAs settings

The correct answer is: A single-phase generator

Minimizing patient exposure during radiologic procedures is essential for ensuring patient safety and maintaining optimal image quality. The correct answer, which indicates a single-phase generator, does not contribute to minimizing patient exposure for several reasons. A single-phase generator produces a voltage waveform that leads to greater fluctuations in the x-ray beam. This results in less efficient x-ray output, requiring higher exposure times and, consequently, higher radiation doses to the patient for adequate image quality. In contrast, more advanced generators, such as three-phase or high-frequency generators, provide a more constant and efficient x-ray output, allowing for lower exposure settings while still maintaining image quality. This efficiency is crucial in reducing the overall radiation dose to patients. On the other hand, options like added tube filtration, beam restriction, and low mAs settings are all strategies employed to minimize patient exposure effectively. Added tube filtration serves to absorb lower-energy photons, reducing patient dose from scatter radiation. Beam restriction limits the size of the x-ray field to the area of interest, thereby minimizing exposure to surrounding tissues. Lower mAs settings reduce the amount of radiation used during the exposure, which directly decreases the dose the patient receives. These methods are critical in optimizing radiographic techniques while safeguarding patient health.