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

As OID increases, the object is farther from the image receptor and closer to the source, causing greater divergence of X-rays and increased magnification.

Question 2

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

Accepted Answer

Patient rotation

Answer

Unequal obturator foramina on an AP pelvis indicate patient rotation, as both foramina should appear symmetric when properly positioned.

Question 3

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

Accepted Answer

The exposure latitude and contrast scale of the imaging system

Answer

A step-wedge produces a range of densities that allows evaluation of the system's exposure latitude, contrast, and density response across different exposure levels.

Question 4

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

Accepted Answer

Air under the diaphragm

Answer

Free intraperitoneal air rises to the highest point in the abdomen and appears as a radiolucent crescent under the diaphragm on an upright view.

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

At greater SID, the X-ray beam approaches parallel rays more closely, reducing geometric unsharpness (penumbra) and improving recorded detail.

(GXMO) General X-Ray Machine Operator Practice Test

(GXMO) General X-Ray Machine Operator Practice Test

GXMO Image Quality and Interpretation 3