Table 2.

Tabulated physical parameters for mass attenuation coefficients at mean energies of kVCT (80 keV) and MVCT (800 keV), water content, hydrogen density, and proton mass stopping power ratios derived from tissue substitute phantom elemental composition versus real tissue composition from ICRU Report 44²² and ICRP Report 23²³.

	μ/ρ (80 keV) × 10−1		μ/ρ (800 keV) × 10−2		Water content		Hydrogen density		SPR/ρ (115 MeV)
	Phantom	Literature	Phantom	Literature	Phantom	Literature	Phantom	Literature	Phantom	Literature
Skin	1.81	1.81	7.78	7.80	0.75	0.59-0.72	0.100	0.100-0.101	0.99	0.99-1.00
Muscle	1.81	1.82	7.80	7.79	0.75	0.70-0.79	0.102	0.101-0.102	0.99	0.99-1.00
Adipose	1.82	1.80	7.88	7.87	0.47	0.11-0.31	0.115	0.112-0.116	1.00	1.00-1.03
Spongiosa	1.90	1.95	7.75	7.67	0.27	0.23	0.096	0.085	0.98	0.98