CAMRT Radiography Practice Exam

In CT imaging, how many collimators are present?

1. Two collimators

2. One collimator

3. Three collimators

4. Four collimators

The correct answer is: Two collimators

In computed tomography (CT) imaging, there are typically two collimators utilized during the imaging process. One collimator is positioned at the x-ray tube, which helps to restrict the beam size and shape before it enters the patient. This not only ensures that only the desired area is imaged but also reduces the patient's exposure to unnecessary radiation by limiting the amount of scattered radiation that can be captured by the detectors. The second collimator is located at the level of the detectors. Its purpose is to further refine the incoming x-rays and to enhance image quality by managing the angles of rays that reach the detectors. The effective use of these collimators plays a critical role in optimizing image quality while minimizing radiation exposure, underscoring the importance of their presence in CT systems.