Radiography Exam Image Production & Processing

Question 1

In digital radiography, what does the exposure index (EI) primarily indicate?

Accepted Answer

The amount of radiation that reached the detector

Answer

The exposure index is a measure of the radiation exposure reaching the digital detector, used to assess whether the detector was properly exposed.

Question 2

Which artifact in computed radiography (CR) appears as a ghost image from a previous exposure due to incomplete erasure?

Accepted Answer

Lag artifact (ghosting)

Answer

Lag (ghosting) occurs when residual signal from a previous exposure is not fully erased from the PSP plate before the next exposure.

Question 3

What is the primary advantage of direct digital radiography (DR) over computed radiography (CR)?

Accepted Answer

Immediate image availability without plate handling

Answer

DR panels provide immediate image display because there is no separate plate processing step, improving workflow efficiency.

Question 4

In digital imaging, which term describes the range of exposure values over which the detector can produce a diagnostic image?

Accepted Answer

Dynamic range

Answer

Dynamic range refers to the range of exposure values (from very low to very high) that a digital detector can accurately capture and display.

Question 5

What happens to image noise (quantum mottle) when mAs is decreased in digital radiography?

Accepted Answer

Noise increases because fewer photons form the image

Answer

Reducing mAs decreases the number of photons reaching the detector, resulting in a noisier (more mottled) image due to quantum noise.

Radiography Exam Practice Test