Where is the pre-patient collimator located in an X-ray system?

• A. On the detectors
• B. On the patient
• C. On the tube head
• D. In the control room

Answer: (C)

The pre-patient collimator is located on the tube head of an X-ray system. Its primary function is to limit the size and shape of the X-ray beam before it reaches the patient. This is crucial for imaging quality and patient safety, as it helps reduce unnecessary radiation exposure by ensuring that only the area of interest receives the X-rays.

By precisely controlling the dimensions and direction of the beam, the pre-patient collimator improves the effectiveness of the imaging process, enhances contrast, and minimizes scatter radiation, which can obscure images. This positioning at the tube head allows for easy adjustments and optimizations of the beam based on the specific diagnostic needs.