Table 4.

Single region of interest analysis: Mean errors of the estimated volume fractions (vf) of bone, fat, and red marrow for each of the six test inserts are listed as are the standard deviations of those errors (in parentheses) for the three repeat scans for each condition. Also listed are the overall RMS errors for all of the test inserts. Standard dose, internal calibration.

Test insert nominal composition (vf)			Mean bone error (vf)			Mean fat error (vf)			Mean red marrow error (vf)
Bone	Fat	Red marrow	S	M	L	S	M	L	S	M	L
0.052	0.800	0.148	0.0023	0.0026	0.0013	0.028	0.038	0.032	−0.031	−0.041	−0.033
			(0.0031)	(0.0040)	(0.0072)	(0.018)	(0.025)	(0.046)	(0.021)	(0.029)	(0.053)
0.104	0.200	0.696	0.0018	0.0012	−0.0055	0.003	0.002	−0.038	−0.006	−0.003	0.043
			(0.0044)	(0.0015)	(0.0058)	(0.031)	(0.043)	(0.036)	(0.035)	(0.050)	(0.041)
0.104	0.300	0.596	(0.0075	0.0015	−0.0008	0.037	−0.003	−0.019	−0.044	0.001	0.020
			(0.0070)	(0.0096)	(0.0074)	(0.043)	(0.061)	(0.047)	(0.050)	(0.070)	(0.054)
0.156	0.100	0.744	0.0051	0.0088	−0.0063	0.047	0.069	−0.032	−0.053	−0.077	0.038
			(0.0012)	(0.0044)	(0.0079)	(0.008)	(0.025)	(0.049)	(0.009)	(0.029)	(0.057)
0.156	0.300	0.544	0.0054	−0.0013	−0.0049	0.016	−0.026	−0.049	−0.021	0.027	0.054
			(0.0045)	(0.0040)	(0.0064)	(0.031)	(0.029)	(0.042)	(0.036)	(0.033)	(0.048)
0.156	0.500	0.344	0.0054	0.0064	0.0011	0.026	0.035	−0.008	−0.031	−0.042	0.007
			(0.0025)	(0.0049)	(0.0078)	(0.017)	(0.031)	(0.043)	(0.020)	(0.035)	(0.051)
Overall RMS error			0.0061	0.0067	0.0071	0.037	0.048	0.048	0.043	0.054	0.055

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