The Hounsfield scale of tissue density is based on two values: air as -1000HU (minimum HU value) and water as 0HU. Density of other tissues is related to this range, usually from -1000 to +1000HU (-1024 to 1024 or 3072 depending on the coding of particular vendor). However, the scale by its the definition is open-ended.
|Lung parenchyma (inspirium)||-850 to -910|
|Fat||-50 to -100|
|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|
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.