Which type of PID contributes to reducing patient radiation exposure?

The rectangular PID is designed to confine the x-ray beam to the actual size of the film or digital sensor, which helps to reduce patient radiation exposure. This is particularly effective because it limits unnecessary radiation that would otherwise be directed toward the patient if a round PID were used, which has a larger beam area.

By focusing the beam more precisely, the rectangular PID minimizes the irradiated area while still capturing the necessary diagnostic information. This reduction in exposure is crucial for adhering to the principle of ALARA (As Low As Reasonably Achievable), which encourages radiation professionals to use the lowest dose possible to achieve adequate imaging.

In contrast, a round PID emits a larger radiation field, creating more scatter and increasing patient exposure. External and recessed PIDs also have their specific applications, but they are not as effective in reducing exposure compared to the rectangular design, specifically regarding beam collimation and efficiency in targeting the area of interest.