The largest difference in signal intensities within the remnant beam of a chest exposure describes which property?

The largest difference in signal intensities within the remnant beam of a chest exposure describes which property?

• A. Low subject contrast
• B. High subject contrast
• C. Low receptor exposure
• D. High receptor exposure

Answer: (C)

The remnant beam is the x-ray energy that actually reaches the image receptor after passing through the patient. The pattern of intensities you see across that remnant beam reflects how much signal the receptor is receiving in different areas, which is governed by the receptor exposure. When exposure to the receptor is low, only a small number of photons reach the detector and tissue differences (air in the lungs, soft tissue, bone) cause more pronounced relative differences in the signals that do get through. That leads to the largest variation in signal intensities within the remnant beam. In other words, unusually large differences across the remnant beam point to insufficient, or low, receptor exposure.

The remnant beam is the x-ray energy that actually reaches the image receptor after passing through the patient. The pattern of intensities you see across that remnant beam reflects how much signal the receptor is receiving in different areas, which is governed by the receptor exposure. When exposure to the receptor is low, only a small number of photons reach the detector and tissue differences (air in the lungs, soft tissue, bone) cause more pronounced relative differences in the signals that do get through. That leads to the largest variation in signal intensities within the remnant beam. In other words, unusually large differences across the remnant beam point to insufficient, or low, receptor exposure.