In digital fluoroscopy and computed radiography, the energy must be changed to a digital form by a(n):

• A. Digital-to-analog converter
• B. Flux capacitor
• C. Analog-to-digital converter
• D. DVD-ROM

Answer: (C)

In digital fluoroscopy and computed radiography, the detector outputs a continuous, analog signal that reflects the x-ray energy detected. To be read, processed, and stored by a computer, that signal must be converted into digital values. An analog-to-digital converter performs this by sampling the analog signal over time and quantizing those samples into discrete digital numbers, turning continuous energy information into digital data the system can use. A digital-to-analog converter would do the opposite, converting digital values back into analog form, which isn’t what is required here. The other options aren’t relevant to converting the detector signal into digital data.