Which of the following tissues is expected to show a Hounsfield Unit value around -50 to -100 HU?

The expected Hounsfield Unit (HU) value for fat typically falls within the range of -50 to -100 HU. Hounsfield Units are a measurement of radiodensity used in computed tomography (CT), where air is assigned a value of -1000 HU and water is given a value of 0 HU. Fat is less dense than water and therefore has a negative value, reflecting its lower attenuation of X-rays in comparison to denser tissues.

Fat appears brighter on CT images compared to air and darker than other soft tissues such as muscle and fluid, which usually have higher HU values. The negative HU values for fat make it easily distinguishable from other surrounding tissues. In contrast, other tissues listed typically have HU values that are not consistent with this range; for example, muscle typically has a HU value closer to +40 to +60, blood has a value generally around +30 to +50, and cerebrospinal fluid usually has a HU value around +10 to +15. Thus, the correct identification of fat's HU range is essential for differentiating between various tissues when interpreting CT scans.