Radiologic Technologist Practice Exam

What is the primary function of a collimator in radiography?

1. to increase patient exposure

2. to define the boundaries of the x-ray beam

3. to enhance the image contrast

4. to detect radiation levels

The correct answer is: to define the boundaries of the x-ray beam

The primary function of a collimator in radiography is to define the boundaries of the x-ray beam. By carefully controlling the size and shape of the x-ray beam, the collimator helps to limit the radiation exposure to both the patient and the surrounding tissues. This is critical in radiographic procedures, as it ensures that only the area of interest is imaged, reducing unnecessary dose to healthy tissues and minimizing the risk of side effects associated with radiation exposure. In addition to enhancing patient safety, the use of a collimator improves the overall quality of the images produced. By narrowing the beam, the collimator assists in reducing scatter radiation, which can degrade image quality. Consequently, this leads to better diagnostic images, as the primary x-ray beam is focused more effectively on the specific area being examined. The other functions suggested by the incorrect choices focus on aspects that do not align with the primary role of a collimator. For instance, the collimator does not increase patient exposure; rather, it is designed to reduce exposure. It does not work to enhance image contrast directly, but rather it contributes indirectly by reducing scatter. Lastly, while detection of radiation levels is an important aspect of radiographic safety, this function lies within the