Difference between revisions of "Hounsfield unit"

From ICRPaedia
Jump to navigation Jump to search
(Created page with "100px|frameless|right|link=ICRP Glossary Number used to represent the mean x-ray attenuation associated with each elemental area of the CT image....")
(No difference)

Revision as of 16:43, 12 August 2021

Glossary Icon-2.png

Number used to represent the mean x-ray attenuation associated with each elemental area of the CT image. Measured values of attenuation are transformed into HU (also known as CT numbers) using the Hounsfield scale:

[math]HU = \frac{(μ_{{material}} - μ_{{water}})} {μ_{{water}}} \cdot 1000[/math]


where μ is the effective linear attenuation coefficient of the measured material relative to water for the x-ray beam used. The scale is defined so that under standard conditions water has a value of 0 HU and air has a value of -1000 HU.

(adapted from ICRP Publication 129, 2015)

Return to Glossary