250 / 1542
Conversion of
m
to CT number
m
values are scaled to that of water to give the
CT number (Hounsfield Unit)
CT number = 1000 x
m
tissue
-
m
water
m
water
-
m
air
TPS: The relative electron density of the
irradiated medium can be determined from
the CT data set via the conversion between
CT numbers and
r
e
Tissue
CT-number (HU)
Air
-1000
Lung
-300
Fat
-90
Water
0
White Matter
30
Gray Matter
40
Muscle
50
Trabecular Bone 300-500
Cortical Bone
600 -3000