Imaging noise is different from quantum noise in that imaging noise

• A. is inherent in the imaging system
• B. is caused by patient motion
• C. is due to scatter radiation
• D. is influenced by processing algorithms

Answer: (A)

In imaging, different noise sources come from different origins. Imaging noise refers to the noise that originates in the imaging system itself—the detectors, electronics, readout circuitry, and how the signal is processed. Because it is tied to the hardware and its operation, this type of noise is essentially built into the system. Quantum noise, on the other hand, comes from the random nature of photon emission and detection (photon statistics). Its magnitude changes with the number of photons (dose), so it isn’t a fixed property of the hardware. The other factors—patient motion, scatter radiation, and processing choices—affect image quality in different ways and aren’t intrinsic to the imaging system’s hardware.