Osteoporosis imaging: effects of bone preservation on MDCT-based trabecular bone microstructure parameters and finite element models

Table 2 Mean ± SD of FEM-based ACM, BMD, and trabecular bone microstructure parameters of the formalin-fixed and frozen vertebrae at baseline, 3 and 6 month follow-up. Changes of the computed parameters over 6 months are expressed as root-mean-square coefficients of variation (RMSCV) and were not significant (p > 0.05) as assessed by using the Friedmann test

	Preservation	Baseline	3 month follow-up	6 month follow-up	RMSCV [%]	p-value
FEM-based ACM [N/mm²]	frozen (n = 6)	498 ± 214	500 ± 197	504 ± 187	4.0	0.846
FEM-based ACM [N/mm²]	formalin (n = 6)	494 ± 164	480 ± 152	494 ± 162	2.9	0.513
BMD [mg/cm³]	frozen (n = 6)	125 ± 34	125 ± 35	124 ± 36	1.3	0.565
BMD [mg/cm³]	formalin (n = 6)	128 ± 34	129 ± 34	129 ± 34	1.0	0.467
app. BV/TV	frozen (n = 6)	0.266 ± 0.121	0.274 ± 0.108	0.277 ± 0.110	5.4	0.311
app. BV/TV	formalin (n = 6)	0.269 ± 0.199	0.261 ± 0.123	0.263 ± 0.114	4.0	0.119
app. TbN [mm⁻¹]	frozen (n = 6)	0.860 ± 0.270	0.864 ± 0.206	0.894 ± 0.248	4.4	0.311
app. TbN [mm⁻¹]	formalin (n = 6)	0.835 ± 0.255	0.832 ± 0.211	0.847 ± 0.264	4.6	0.846
app. TbSp [mm]	frozen (n = 6)	0.990 ± 0.479	0.923 ± 0.367	0.910 ± 0.398	6.1	0.223
app. TbSp [mm]	formalin (n = 6)	1.048 ± 0.555	1.035 ± 0.507	1.047 ± 0.559	5.6	0.846
app. TbTh [mm]	frozen (n = 6)	0.295 ± 0.050	0.307 ± 0.053	0.301 ± 0.041	3.0	0.119
app. TbTh [mm]	formalin (n = 6)	0.308 ± 0.056	0.298 ± 0.069	0.297 ± 0.052	4.0	0.135
FD	frozen (n = 6)	1.453 ± 0.145	1.472 ± 0.114	1.484 ± 0.139	2.0	0.311
FD	formalin (n = 6)	1.471 ± 0.151	1.470 ± 0.134	1.459 ± 0.159	2.6	0.607

FEM finite element model, ACM apparent compressive modulus, BMD bone mineral density, app. BV/TV apparent bone volume divided by total volume, app. TbN apparent trabecular number, app. TbSp apparent trabecular separation, app. TbTh apparent trabecular thickness, FD fractal dimension

ISSN: 1471-2342