Table 5.

Single region vs multiple subregion analysis: Overall RMS errors of the volume fractions of bone, fat, and red marrow of the six test inserts. Standard dose, internal calibration.

Standard (1×) dose		Bone RMS error (vf)			Fat RMS error (vf)			Red marrow RMS error (vf)
Partition	Region/subregion size (mm)	S	M	L	S	M	L	S	M	L
1 × 1	17 × 17	0.0061	0.0067	0.0071	0.037	0.048	0.048	0.043	0.054	0.055
2 × 2	9 × 9	0.0092	0.0116	0.0141	0.060	0.078	0.091	0.069	0.089	0.105
3 × 3	6 × 6	0.0140	0.0169	0.0202	0.092	0.110	0.127	0.106	0.126	0.147

¹S = small phantom; M = medium phantom; L = large phantom.