American Society of Radiologic Technologist (ASRT) Practice Exam

Which type of switch increases the safety of fluoroscopic procedures?

1. Positive-pressure switch

2. Negative-pressure switch

3. Toggle switch

4. Variable resistor

The correct answer is: Positive-pressure switch

In fluoroscopic procedures, ensuring the safety of both the patient and the personnel is paramount. A positive-pressure switch increases safety by requiring continuous operator engagement to maintain the flow of radiation. This type of switch mandates that the radiologic technologist or operator must actively hold the switch to keep the imaging system active, ensuring that exposure to radiation is controlled and minimized to the necessary times. When safety devices like a positive-pressure switch are in place, they reduce the risk of unintended exposure by only allowing radiation to be emitted while the switch is physically engaged. This design encourages operators to maintain awareness and responsibility during the procedure, reinforcing the importance of monitoring both the patient and the equipment. In contrast, devices such as toggle switches or negative-pressure switches do not actively promote continuous engagement, which could lead to longer unintended exposures. Variable resistors do not specifically relate to the safety mechanisms controlling radiation emission in fluoroscopy.