Too much mAs will cause quantum mottle.

• A. True
• B. False
• C. Depends on technique
• D. Cannot be determined

Answer: (B)

Quantum mottle is the grainy noise that appears when too few photons reach the detector. The number of photons is set by mAs, so increasing mAs increases photon flux and reduces the random fluctuations that produce this noise. So, too much mAs does not cause quantum mottle; it actually helps suppress it (though it raises patient dose and can cause other problems like detector saturation or motion blur). The correct idea is that quantum mottle decreases with higher exposure, not increases.