Too little mAs can cause which artifact?

• A. Quantum mottle
• B. Motion blur
• C. Grid cut-off
• D. Noise

Answer: (A)

When mAs is too low, not enough photons reach the detector, so the image ends up with random fluctuations in brightness called photon starvation. This shows up as a grainy, mottled appearance known as quantum mottle. The reduction in photon statistics degrades image quality by increasing noise and reducing the ability to discern detail, especially in uniform areas.

Motion blur comes from patient or tube movement during the exposure, not from low mAs. Grid cut-off occurs when the x-ray beam is not properly aligned with the grid. Noise is a general term for random variations, but the specific artifact tied to insufficient exposure is quantum mottle, which is why that option best fits.