Optimization of Image Quality and Organ Absorbed Dose for Pediatric Chest X-Ray Examination: In-House Developed Chest Phantom Study

Table 1

The comparison of density and CT numbers of human tissue and tissue substitute materials. Polyester resin, polyester resin with 40% CaCO₃, and polyurethane foam were used as soft tissue, bone, and lung, tissue-equivalent materials, respectively.

	Density (g/cm^3)			CT number (HU)
	Soft tissue	Bone	Lung	Soft tissue	Bone	Lung
Human tissue	1.06	1.6 to 2	0.26	40 to 80	400 to 1000	−400 to −600
Tissue substitutes used	1.12	n/a	0.30	112.8 ± 4.1	587.2 ± 51.1	−955.5 ± 1.4
% Difference	5.3	—	15.8	41	−41.3	59.3

n/a is not assessed.