Relationship between architectural parameters and sample volume of human cancellous bone in micro-CT scanning

Truly representative architectural parameters of trabeculea can be extremely difficult to achieve based on scanning images because of variable porosity and distribution of trabeculae within the specific overall scanned volume of bone. Accordingly, in present study different selective volume of interests, measured from centroid of μ-CT scanned human vertebral body, were analyzed to determine the architectural parameters (BV/TV, BS/BV, Tb.Th, Tb.N, Tb.Sp) of trabeculae within these volumes and to suggest an optimal volume for representative architectural parameters of the overall scanned volume. Nonlinear curve fitting method was also applied to obtain the correlation between the parameters and the volume of interests. The results show different volumes of interests give different morphological indices of BV/TV, BS/BV, Tb.N and Tb.Sp within a specific scanned vertebral body. Tb.Th shows relatively small variation (0.8%) even with sample volume of less than (2 mm)3. Statistical analysis shows that with sample volume of less than (6 mm)3, significant different in the measured BV/TV comparing against the control group. Tb.N and Tb.Sp show significant different values against the control group for volume of interest less than (4 mm)3 and (5 mm)3, respectively. However, no significant differences were observed in the indices of BS/BV and Tb.Th. Present study shows that an optimal volume of interests of greater than (6 mm)3 be selected to predict the architectural parameters of trabeculae of human vertebral bodies.