ARRT - American Registry of Radiologic Technologists Image Acquisition and Evaluation Questions and Answers

Question 1

In computed radiography (CR), what is the primary function of the photostimulable phosphor (PSP) within the imaging plate?

Accepted Answer

To absorb the remnant beam energy and store it as a latent image.

Answer

To convert the latent image directly into a digital signal.

Answer

To emit light instantaneously upon x-ray exposure.

Answer

To focus the electron beam during the image reading process.

Question 2

A radiograph of an AP abdomen appears grainy and mottled. The exposure indicator value is significantly lower than the target range. Which of the following technical adjustments would be most effective in correcting this quantum mottle artifact on a repeat exposure?

Accepted Answer

Increase the mAs.

Answer

Increase the grid ratio.

Answer

Decrease the kVp.

Answer

Increase the Source-to-Image Distance (SID).

Question 3

When changing from an 8:1 ratio grid to a 12:1 ratio grid for a particular examination, which of the following consequences should the technologist anticipate?

Accepted Answer

An increase in image contrast.

Answer

A decrease in patient radiation dose.

Answer

A decrease in the required mAs.

Answer

An increase in the amount of scatter reaching the receptor.

Question 4

A technologist is performing a lateral lumbar spine using an Automatic Exposure Control (AEC) system. The patient is positioned correctly, but the resulting image is significantly underexposed. Which of the following is the most likely cause of this error?

Accepted Answer

The backup timer was set too low.

Answer

The density control was set to +2.

Answer

The central ray was centered to the AEC detectors.

Answer

The kVp selected was too high for the body part.

Question 5

While reviewing a portable chest radiograph acquired with a DR flat-panel detector, the technologist notices a faint, reversed image of the detector's electronic wiring superimposed over the patient's anatomy. This artifact is known as:

Accepted Answer

Backscatter

Answer

Moiré effect

Answer

Image lag

Answer

Dead pixel artifact

Question 6

A digital radiograph of a knee is produced with optimal brightness and contrast. However, the Deviation Index (DI) value is +2.5. How should the technologist interpret this value?

Accepted Answer

The image is significantly overexposed, and the mAs should be reduced for future similar exams.

Answer

The image is slightly underexposed, and the technique should be increased.

Answer

The exposure to the image receptor was perfect.

Answer

The image has a poor signal-to-noise ratio.