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Micro-CT for bone structural analysis has progressed from an in-vitro laboratory technique to devices for in-vivo
assessment of small animals and the peripheral human skeleton. Currently, topological parameters of bone architecture
are the primary goals of analysis. Additional measurement of the density or degree of mineralization (DMB) of
trabecular and cortical bone at the microscopic level is desirable to study effects of disease and treatment progress. This
information is not commonly extracted because of the challenges of accurate measurement and calibration at the tissue
level. To assess the accuracy of micro-CT DMB measurements in a realistic but controlled situation, we prepared bone-mimicking
watery solutions at concentrations of 100 to 600 mg/cm3 K2PO4H and scanned them with micro-CT, both in
glass vials and microcapillary tubes with inner diameters of 50, 100 and 150 mm to simulate trabecular thickness. Values
of the linear attenuation coefficients m in the reconstructed image are commonly affected by beam hardening effects for
larger samples and by partial volume effects for small volumes. We implemented an iterative reconstruction technique to
reduce beam hardening. Partial voluming was sought to be reduced by excluding voxels near the tube wall. With these
two measures, improvement on the constancy of the reconstructed voxel values and linearity with solution concentration
could be observed to over 90% accuracy. However, since the expected change in real bone is small more measurements
are needed to confirm that micro-CT can indeed be adapted to assess bone mineralization at the tissue level.
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