A lateral sacral projection with poor positioning demonstrates a closed L5-S1 intervertebral disk space and foreshortening of the sacrum. How could the positioning setup have been mispositioned for such a projection to be obtained?
1)The patient was rotated.
2)The central ray was angled too cephalically.
3)The vertebral column was not aligned parallel with the imaging table.
4)The patient's legs were extended.
A) 1 only
B) 2 and 3 only
C) 3 only
D) 1 and 4 only

Question

Quizplus · Accepted Answer

Foreshortening of the sacrum and a closed L5-S1 intervertebral disk space on a lateral sacral projection are caused by angling the central ray too cephalic and by not aligning the vertebral column parallel with the imaging table. Rotating the patient or extending their legs would not result in this type of image artifact. Therefore, options 1 and 4 can be eliminated. Option 3 is the main cause of foreshortening of the sacrum, but it does not cause a closed L5-S1 intervertebral disk space. Hence, the correct answer is option B, which includes both 2 and 3.

A Lateral Sacral Projection with Poor Positioning Demonstrates a Closed