American Society of Radiologic Technologist (ASRT) Practice Exam

Which statement correctly describes the need to change technical factors from an AP lumbar spine to an oblique lumbar spine image?

1. The abdomen becomes denser; technique must increase

2. The abdomen becomes less dense; technique must decrease

3. The abdomen becomes thicker; technique must increase

4. The abdomen becomes less thick; technique must decrease

The correct answer is: The abdomen becomes thicker; technique must increase

The chosen statement reflects a key understanding of how body positioning affects radiographic imaging, specifically concerning the technical factors used during the examination of the lumbar spine. When transitioning from an anteroposterior (AP) lumbar spine to an oblique lumbar spine image, there is indeed an increase in the thickness or volume of the tissue the X-ray beams must penetrate. In an AP view, the radiation primarily passes through structures positioned directly behind each other, while the oblique view requires the beam to traverse through a greater thickness of tissue, particularly because the body is angled. This increase in thickness necessitates an increase in technical factors, such as kilovoltage (kV) or milliampere-seconds (mAs), to ensure adequate exposure and image quality. These adjustments are crucial for achieving a clear and diagnostic image by overcoming the additional density introduced by the body's anatomy in the oblique position. The understanding of which technical factors to modify based on body density and thickness is essential for producing optimal radiographic images.