CAMRT - Canadian Association of Medical Radiation Technologists Image Production and Quality Questions and Answers

Question 1

A digital radiograph of a knee appears excessively noisy and grainy.
The exposure indicator (EI) is significantly below the target range.
Which of the following is the most likely cause for this appearance?

Accepted Answer

Insufficient mAs

Answer

Incorrect look-up table (LUT) applied

Answer

Excessive Object-to-Image Distance (OID)

Answer

Use of a high-ratio grid

Question 2

Which of the following technical factor adjustments will increase the penetrability of the x-ray beam, resulting in lower image contrast?

Accepted Answer

Increasing the kVp

Answer

Increasing the mAs

Answer

Decreasing the SID

Answer

Using a smaller focal spot

Question 3

An MRT is performing a CT scan of the head. The resulting axial images show dark, streak-like artifacts and a 'cupping' artifact where the central portion of the brain parenchyma appears artificially dark. This is most characteristic of:

Accepted Answer

Beam hardening artifact

Answer

Motion artifact

Answer

Ring artifact

Answer

Partial volume averaging

Question 4

In digital radiography, what is the primary purpose of applying a look-up table (LUT) during image processing?

Accepted Answer

To map raw pixel data to specific brightness and contrast levels for display

Answer

To calculate the patient's effective dose from the exposure

Answer

To reduce geometric unsharpness caused by the focal spot size

Answer

To select the appropriate kVp and mAs for the examination

Question 5

Which combination of geometric factors will result in the highest degree of image unsharpness (penumbra)?

Accepted Answer

Large focal spot, short SID, long OID

Answer

Small focal spot, long SID, short OID

Answer

Large focal spot, long SID, short OID

Answer

Small focal spot, short SID, long OID

Question 6

An MRT performs a portable chest x-ray using a focused grid. The resulting image demonstrates severe grid cut-off on both lateral edges, while the central portion of the image is properly exposed. What is the most likely cause of this artifact?

Accepted Answer

The grid was placed upside-down

Answer

An off-level grid error

Answer

The SID was outside the grid's focal range

Answer

An off-center grid error