CAMRT Radiography Practice Exam

What is the expected technical factor adjustment when using the Air Gap technique?

1. Decreased exposure time

2. Increased exposure time

3. Reduced voltage

4. Higher mAs setting

The correct answer is: Increased exposure time

The Air Gap technique is employed to reduce scatter radiation by increasing the distance between the patient and the image receptor. This results in less scatter reaching the receptor, which can enhance image contrast. However, because some of the primary beam is lost or attenuated due to this added distance, an adjustment in technical factors is necessary to ensure optimal image quality. When implementing the Air Gap technique, the exposure must be adjusted to compensate for the loss of intensity at the image receptor. This often necessitates increasing the exposure time to allow more radiation to reach the image receptor to maintain image quality. The longer exposure allows for an adequate amount of radiation to penetrate to produce a properly exposed image despite the effects of scattering being minimized. This adjustment contrasts with other methods that might decrease exposure time or reduce overall exposure settings, which would not suffice under the conditions presented by the Air Gap technique. As a result, the increase of exposure time aligns perfectly with the goal of offsetting the loss of radiation that occurs due to the spatial separation aided by the air gap.