Which tissue yields the highest signal intensity at the image receptor?

Which tissue yields the highest signal intensity at the image receptor?

• A. Liver
• B. Spine
• C. Spleen
• D. Bowel Gas

Answer: (D)

Signal at the image receptor depends on how much the tissue attenuates the X-ray beam. Gas attenuates very little because it’s low density, so most photons pass through and reach the detector, giving the highest signal intensity. Gas is radiolucent and appears dark on radiographs, reflecting that strong detector signal. In contrast, liver and spleen are denser soft tissues and absorb more photons, reducing the signal at the receptor, and bone in the spine attenuates the most, producing the least signal. So bowel gas yields the highest signal intensity at the image receptor.

Signal at the image receptor depends on how much the tissue attenuates the X-ray beam. Gas attenuates very little because it’s low density, so most photons pass through and reach the detector, giving the highest signal intensity. Gas is radiolucent and appears dark on radiographs, reflecting that strong detector signal. In contrast, liver and spleen are denser soft tissues and absorb more photons, reducing the signal at the receptor, and bone in the spine attenuates the most, producing the least signal. So bowel gas yields the highest signal intensity at the image receptor.