Table 2. Correlations between metaphyseal BMD and bone structural parameters derived by bone histomorphometry, in vivo μCT, or ex vivo specimen μCT 10 weeks after tumor inoculation.

Technique and parameter	Model	Threshold (HU)	r	P
In vivo μCT, 91 µm vs Histomorphometry
TbN	O*	400	0.81	<0.001
	A*	633±220	0.53	<0.02
TbSp	O	400	0.78	<0.001
	A	633±220	0.60	<0.002
BV/TV	O	400	0.73	<0.001
	A	633±220	0.58	<0.003
BMD	O	400	0.78	<0.001
	A	633±220	0.78	<0.001
Ex vivo μCT, 31 µm vs Histomorphometry
Tb N	O	2000	0.78	<0.001
	A	1830±650	0.61	<0.002
Tb Sp	O	2000	0.73	<0.001
	A	1830±650	0.57	<0.001
BV/TV	O	2000	0.79	<0.001
	A	1830±650	0.58	<0.001
BMD	O	2000	0.75	<0.001
	A	1830±650	0.75	<0.001
Ex vivo μCT, 16 µm vs Histomorphometry
Tb N	O	2000	0.88	<0.02
	A	2423±770	0.73	<0.3
Tb Sp	O	2000	0.8	<0.001
	A	2423±770	0.61	<0.001
BV/TV	O	2000	0.82	<0.001
	A	2423±770	0.69	<0.001
BMD	O	2000	0.77	<0.001
	A	2423±770	0.77	<0.001
Ex vivo μCT, 8 µm vs Histomorphometry
TbN	O	3000	0.90	<0.001
	A	1822±920	0.71	<0.001
TbSp	O	3000	0.84	<0.001
	A	1822±920	0.69	<0.001
BV/TV	O	3000	0.83	<0.001
	A	1822±920	0.71	<0.001
BMD	O	3000	0.84	<0.001
	A	1822±920	0.83	<0.001

*O, optimal threshold; A, automatic threshold.