Hounsfield Unit

Hounsfield Unit, HU

2. Hounsfield units - scale of HU, CT numbers
•The Hounsfield unit (HU) is a quantity commonly used 
in computed tomography (CT) scanning to express CT 
numbers in a standardised and convenient form. 
Hounsfield units, created by and named after 
Sir Godfrey Hounsfield found it in 1971.
•Through a mathematical calculation, the computer 
construct a graphic image, assigning a number (called 
Hounsfiled unit ) to represent radiodensity at each 
point

3. Matter Density (HU)
Air -500 to -1000
Lung parenchyma (inspirium) -200 to -400
Fat -50 to -100
Water 0
White matter 20 to 30HU
Kidney 20 to 40HU
Spleen 35 to 55HU
Grey matter 37 to 45HU
Blood 45 to 65HU
Liver 45 to 65HU
Hematoma 40 to 90HU
Bone 700 to 3000
Hounsfield units - scale of HU, CT numbers

4. Hounsfield units - scale of HU, CT numbers

5. REFERENCES
1. Buzug TM. Computed Tomography: From
Photon Statistics to Modern Cone-Beam CT.
Springer; 2008:475.
2. Heymsfield S. Human Body Composition.
Human Kinetics; 2005.
3. Prokop M. Spiral and Multislice Computed
Tomography of the Body. Thieme; 2003.

6. REFERENCES
1. Buzug TM. Computed Tomography: From
Photon Statistics to Modern Cone-Beam CT.
Springer; 2008:475.
2. Heymsfield S. Human Body Composition.
Human Kinetics; 2005.
3. Prokop M. Spiral and Multislice Computed
Tomography of the Body. Thieme; 2003.