GXMO Image Quality and Interpretation 3

Question 1

Which of the following describes the relationship between OID (object-to-image distance) and magnification?

Accepted Answer

Increasing OID increases magnification

Answer

Decreasing OID increases magnification

Answer

OID has no effect on magnification

Answer

Increasing OID decreases penumbra

Question 2

On an AP pelvis radiograph, the obturator foramina appear unequal in size. What does this indicate?

Accepted Answer

Patient rotation

Answer

Overexposure of the film

Answer

Incorrect central ray angulation

Answer

Grid cutoff artifact

Question 3

What does a step-wedge (penetrometer) image primarily evaluate?

Accepted Answer

The exposure latitude and contrast scale of the imaging system

Answer

The focal spot size of the X-ray tube

Answer

The accuracy of the collimator light field

Answer

The grid alignment and ratio

Question 4

Which radiographic finding is most characteristic of free air (pneumoperitoneum) on an upright abdominal radiograph?

Accepted Answer

Air under the diaphragm

Answer

Air-fluid levels in the bowel

Answer

Soft tissue calcifications

Answer

Loss of psoas muscle shadow

Question 5

What effect does increasing the source-to-image distance (SID) have on image sharpness, assuming all other factors remain constant?

Accepted Answer

Sharpness increases because geometric unsharpness decreases

Answer

Sharpness decreases because beam divergence increases

Answer

Sharpness is unchanged because SID does not affect penumbra

Answer

Sharpness decreases because mAs must be increased

Question 6

Which type of grid is designed to be used at a specific SID range and will produce grid cutoff if used outside that range?

Accepted Answer

Focused grid

Answer

Parallel grid

Answer

Cross-hatch grid

Answer

Moving (Bucky) grid

Question 7

When reviewing an image for diagnostic quality, which criterion confirms adequate penetration on a lateral thoracic spine radiograph?

Accepted Answer

Intervertebral disc spaces are visible through the superimposed shoulders

Answer

The spinous processes are clearly visualized

Answer

The lung fields appear uniformly radiolucent

Answer

The ribs are visible without overexposure