CAMRT Radiography Practice Exam

What occurs to the patient dose when using increased field size and all other factors are unchanged?

1. Decreased dose

2. No change in dose

3. Increased dose

4. Often varies by patient specifics

The correct answer is: Increased dose

When the field size is increased while keeping all other factors constant, the patient dose generally increases. This is primarily due to the fact that a larger field size allows more of the incident radiation to be directed toward the patient. In radiography, the amount of radiation exposure to the patient is influenced by the area being irradiated. A larger field will encompass more tissue, which means that more radiation is delivered overall to the patient. This typically results in a higher dose because a larger volume is being exposed to the primary beam, increasing the number of photons interacting with the patient's tissues. This is especially relevant in procedures where precise localization of the region of interest is important, and it highlights the need for judicious management of field size to balance image quality and patient safety. Therefore, as the field size increases, so does the potential dose to the patient, leading to the conclusion that this choice is correct.