Which tissue type has the highest Hounsfield unit values on CT?

Which tissue type has the highest Hounsfield unit values on CT?

• A. Bone.
• B. Water.
• C. Fat.
• D. Air.

Answer: (A)

Hounsfield units on CT quantify how dense a tissue is, with a reference scale where water is 0, air is around -1000, and fat is negative to mildly positive. Among common tissues, bone is the densest, and cortical bone typically yields values in the hundreds to about a thousand HU or more. Because of that extreme density, bone stands out with the highest HU values compared with water, fat, or air. Water sits at 0 HU, fat is roughly -100 HU, and air is about -1000 HU, all well below bone’s range. So the tissue with the highest Hounsfield units in this set is bone.

Hounsfield units on CT quantify how dense a tissue is, with a reference scale where water is 0, air is around -1000, and fat is negative to mildly positive. Among common tissues, bone is the densest, and cortical bone typically yields values in the hundreds to about a thousand HU or more. Because of that extreme density, bone stands out with the highest HU values compared with water, fat, or air. Water sits at 0 HU, fat is roughly -100 HU, and air is about -1000 HU, all well below bone’s range. So the tissue with the highest Hounsfield units in this set is bone.