Question

If the center photocell were selected for a lateral projection of the lumbar spine that was positioned with the spinous processes instead of the vertebral bodies centered to the grid, how would the resulting radiograph look?

The image would be underexposed

Answer 1

An incorrectly centered lateral lumbar spine radiograph that targets the spinous processes rather than the vertebral bodies will result in an underexposed image with insufficient detail because the exposure setting is calibrated for the denser vertebral bodies.

Step-by-step explanation:

When a lateral projection of the lumbar spine is carried out with the spinous processes centered to the grid instead of the vertebral bodies, and the center photocell is selected, the resulting radiograph would likely appear underexposed. This underexposure occurs because photocells are calibrated for a specific density and when adjusted for the denser central part of the vertebral bodies, the less dense spinous processes will not provide enough exposure for a properly balanced image.

The lateral projection of the lumbar spine usually captures the profile of the vertebral bodies, which are thicker and denser than the spinous processes.

Therefore, a central cell activated by the spinous processes might suggest to the automatic exposure control (AEC) that less radiation is needed. This will result in an underexposed image, where the diagnostic details in the vertebral bodies will be insufficiently visible.