Hounsfield units
Hounsfield units
Hounsfield units
Hounsfield units are units universally used in
[A] MRI
[B] CT Scan
[C] PET Scan
[D] Angiogram
Hounsfield units (HU) are a dimensionless unit universally used in computed tomography (CT) scanning to express CT numbers
Hounsfield units are obtained from a linear transformation of the measured attenuation coefficients This transformation is based on the arbitrarily-assigned radiodensities of air and pure water:
- Radiodensity of distilled water at standard temperature and pressure (STP) equals 0 HU
- Radiodensity of air at STP equals –1000 HU
Note: STP is defined as temperature of 0 °C and pressure of 105 pascals (i.e. sea-level)
