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Hounsfield Unit

Definition
1. XRay attenuation unit used in CT Scan interpretation
2. Characterizes the relative density of a substance
3. Each pixel is assigned a value between -1k to 1k
Indication
1. Computed Tomographic Scanning (CT Scan)
Substance densities in Hounsfield Units
1. Air: -1000
2. Fat: -50
3. Water: 0
4. Soft tissue such as muscle: +40
5. Calculus: +100 to +400
6. Bone: +1000
References
1. Hounsfield (1980) Med Phys 7:283

Hounsfield unit (C1552985)
Definition (HL7V3.0)	1
Definition (HL7V3.0)	1
Concepts	Quantitative Concept (T081)
English	Hounsfield unit
Parent Concepts	UnitOfMeasureAtomInsens (C1700836), UnitOfMeasureAtomSens (C1701904)
Sources	HL7V3.0 Derived from the NIH UMLS (Unified Medical Language System)

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Hounsfield Unit

Hounsfield unit (C1552985)

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