hounsfield2density
Convert Hounsfield units to density.
Syntax
density = hounsfield2density(ct_data)
density = hounsfield2density(ct_data, plot_fitting)
[density, sound_speed] = hounsfield2density(ct_data)
[density, sound_speed] = hounsfield2density(ct_data, plot_fitting)
Description
hounsfield2density converts Hounsfield units to units of density [kg/m^3] based on the experimental data given by Schneider, U., Pedroni, E., and Lomax A., "The calibration of CT Hounsfield units for radiotherapy treatment planning," Phys. Med. Biol., 41, pp. 111-124 (1996). The conversion is made using a four-part piece-wise linear fit to the data (see figure below). For soft-tissue, the approximate sound speed can also be returned using the empirical relationship given by Mast, T. D., "Empirical relationships between acoustic parameters in human soft tissues," Acoust. Res. Lett. Online, 1(2), pp. 37-42 (2000).
Inputs
ct_data |
CT data in Hounsfield units to convert to density |
Optional Inputs
plot_fitting |
Boolean controlling whether the original data points and fitting is plotted (default = false) |
Outputs
density |
density in kg/m^3 |
sound_speed |
sound speed in m/s |