Table 1. Fraction by weight of each element used in Monte Carlo simulations for various Gd concentrations.

Concentration	Gd	C	H	N	O
1 mg/mL	0.0011	0.0043	0.1107	0.0005	0.8833
3 mg/mL	0.0030	0.0119	0.1100	0.0013	0.8737
5 mg/mL	0.0050	0.0200	0.1093	0.0022	0.8633
10 mg/mL	0.0100	0.0398	0.1076	0.0045	0.8381
15 mg/mL	0.0150	0.0594	0.1058	0.0067	0.8130
20 mg/mL	0.0197	0.0783	0.1041	0.0088	0.7889

The simulated materials are mixtures of motexafin gadolinium and water.