Table 3.

Attenuation coefficients of breast tissues and phantom materials. The information was obtained from a published database by National Institute of Standards and Technology (Ref. ²⁸)

Energy (keV)	Mass attenuation coefficients (g∕cm2)			Linear attenuation coefficients (1∕cm)
		Glandular	Adipose	PMMA	Glandular	Adipose	PMMA
15	1.38	1.08	1.10	1.41	1.03	1.31
18	0.88	0.71	0.71	0.89	0.67	0.85
20	0.69	0.57	0.57	0.70	0.54	0.68
22	0.57	0.48	0.48	0.58	0.45	0.57
25	0.45	0.39	0.39	0.46	0.37	0.46
30	0.34	0.31	0.30	0.35	0.29	0.36