When reviewing a radiographic exposure indicator, a sensitivity number significantly below 200 indicates what about receptor exposure?

When reviewing a radiographic exposure indicator, a sensitivity number significantly below 200 indicates what about receptor exposure?

• A. Insufficient image contrast
• B. Excessive image contrast
• C. Insufficient receptor exposure
• D. Excessive receptor exposure

Answer: (C)

The key idea is that the sensitivity (exposure) indicator reflects how much radiation reached the image receptor. A target value around 200 is used as the guideline for adequate exposure on this system. If the reading is significantly below 200, the receptor did not receive enough exposure, so the image will have a weak signal, higher graininess, and reduced visibility of detail—this is underexposure to the receptor. The other concepts are about how the image looks in terms of grayscale (contrast), which is not what the exposure indicator directly measures. Overexposure would yield a reading above the target, not below.

The key idea is that the sensitivity (exposure) indicator reflects how much radiation reached the image receptor. A target value around 200 is used as the guideline for adequate exposure on this system. If the reading is significantly below 200, the receptor did not receive enough exposure, so the image will have a weak signal, higher graininess, and reduced visibility of detail—this is underexposure to the receptor. The other concepts are about how the image looks in terms of grayscale (contrast), which is not what the exposure indicator directly measures. Overexposure would yield a reading above the target, not below.