Which tissue typically has one of the highest Hounsfield unit values on CT?

Which tissue typically has one of the highest Hounsfield unit values on CT?

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

Answer: (C)

Hounsfield units quantify how much a tissue attenuates X-rays on CT, with water set at 0, air around -1000, fat near -100 to -50, and muscle in the tens. Bone stands out because its dense mineralized matrix drastically increases X-ray absorption. Cortical bone often measures around 1000 HU or higher, while cancellous bone is still much higher than soft tissues. That high attenuation makes bone appear very bright on CT compared with air (very dark), fat (negative to slightly positive), and muscle (modestly bright).

Hounsfield units quantify how much a tissue attenuates X-rays on CT, with water set at 0, air around -1000, fat near -100 to -50, and muscle in the tens. Bone stands out because its dense mineralized matrix drastically increases X-ray absorption. Cortical bone often measures around 1000 HU or higher, while cancellous bone is still much higher than soft tissues. That high attenuation makes bone appear very bright on CT compared with air (very dark), fat (negative to slightly positive), and muscle (modestly bright).