If the image is underexposed, which adjustment could be made?

• A. Either kV or mAs needs to be increased
• B. Increase time (s) only
• C. Only mA should be increased
• D. Increase kV only

Answer: (A)

When an image is underexposed, not enough photons reach the detector to create a clear image. The amount reaching the receptor is governed mainly by mAs (the product of tube current and exposure time) and by kV (beam energy). To fix underexposure, you can increase the exposure by raising the number of photons (increase mAs) or by increasing beam energy (increase kV). Increasing mAs can be done by raising the tube current or by extending the exposure time; both raise the photon count. Increasing kV boosts the beam’s penetration, allowing more photons to reach the receptor, though it also affects image contrast. So, the adjustment could be to increase either mAs (via time or current) or kV, which is why this option is the best fit.