What is the primary function of the analog-to-digital converter in a CR imaging system?

• A. Electrical signal into a digital signal
• B. Light photons into an electrical signal
• C. X-rays into a light signal
• D. Electrical signals to x-ray energy

Answer: (A)

The analog-to-digital converter's job is to take the continuous electrical signal produced by the photodetector (which converts the light from the phosphor into electricity) and convert it into a digital form that the computer can process and store. This step, known as digitizing the signal, involves sampling the voltage at intervals and quantizing those samples into discrete digital levels. All the preceding light-to-electrical conversion and the x-ray to light interactions happen before this, but only the ADC turns that continuous signal into digital data ready for image processing.