Dear all,
I would like to know how exactly the density range used to assign density to material is determined in Data.dat file (DICOM extended example).
Following is the density range provided by the example.
#######################################
# Density Range Materials
#---------------------------------------------------
# g/cm3 -
#---------------------------------------------------
# [ 0.100 , 0.351 ] Lungs (inhale)
# [ 0.351 , 0.919 ] Lungs (exhale)
# [ 0.919 , 0.979 ] Adipose
# ] 0.979 , 1.004 ] Breast
# ] 1.004 , 1.043 ] Phantom
# ] 1.043 , 1.109 ] Liver
# ] 1.109 , 1.113 ] Muscle
# ] 1.113 , 1.400 ] Trabecular Bone
# [ 1.496 , 1.654 ] Dense Bone
#######################################
It’s stated in the README file “Data taken from the International Commission on Radiation Units and measurements (ICRU) report 46 was used to build the materials (lung, liver, breast, bones, …)”. It’s also stated in http://www.nucleaire.phy.ulaval.ca/phys_med/DICOM/index.html#structure_of_data.dat that the density range is just a very rough approximation and is applicable to the used phantom only.
I am quite confused, where exactly the numbers come from. I have checked the ICRU report 46. The report provides for instance electron density and mass density. None of the density value above similar to the values provided by the report. Okay, its roughly approximated, but how was the approximation made?.
Thank you so much for helping.