In radiography, what is the primary reason for using tight collimation?

• A. Reduces patient exposure
• B. Increases retakes
• C. Has no effect
• D. Increases patient exposure

Answer: (A)

Limiting the x-ray field to the anatomy of interest directly reduces the amount of tissue exposed to radiation. A smaller field means less skin dose and fewer tissues irradiated, which lowers the overall radiation burden on the patient. It also reduces scatter within the body, which can improve image contrast. Therefore, the primary reason for tight collimation is to minimize patient exposure. Options suggesting increased exposure or no effect aren’t correct because narrowing the beam inherently lowers the irradiated volume and the resulting dose.