What is the function of the air-gap technique in radiography?

The air-gap technique in radiography serves primarily to reduce the dose to the patient while maintaining image quality. This technique involves positioning the imaging receptor at a certain distance away from the patient, creating an air space between the patient and the receptor. The air gap allows scattered radiation—produced when the primary x-ray beam interacts with the patient's tissues—to dissipate before it reaches the imaging receptor.

This reduction in scatter radiation means that the receptor primarily captures the primary radiation, which improves the overall contrast and clarity of the image without necessitating an increase in the dose of radiation that the patient receives. Hence, while other factors in radiography can be adjusted to enhance resolution, improve patient comfort, or extend exposure time, the primary purpose of the air-gap technique is its effectiveness in minimizing radiation exposure to the patient while preserving adequate image quality.