ACTUAL Exam Questions and CORRECT
Answers
What is indirect capture digital imaging? - CORRECT ANSWER - A DR unit whose IR
first converts incoming x-rays directly into light by using a CCD or CMOS
What is the oldest indirect conversion digital radiography system used to acquire a digital image?
- CORRECT ANSWER - Charge-Coupled Devices (CCD)
How does a CCD work? - CORRECT ANSWER - small capacitors convert the light into
an electrical charge; the charge is stored in a sequential pattern and released line by line and sent
to an ADC
Who developed CMOS systems? - CORRECT ANSWER - NASA
How does a CMOS work? - CORRECT ANSWER - the c-rays are converted into light
photons and stores them in capacitors; each pixel has its own amplifier converting the light
photons into electrical charges
What are both CCD and CMOS technologies based on? - CORRECT ANSWER - arrays of
light sensitive pixels which gather photons of light and convert them to a visible image
What do both types of sensors accomplish? - CORRECT ANSWER - capturing light and
converting it into electrical signals
What material is the chip composed of in a CCD? - CORRECT ANSWER - silicon
What happens when incident light from a scintillator strikes the detector? - CORRECT
ANSWER - electron-hole pairs are produced in the silicon