Mehrschicht-CT zur strukturanalyse des trabekulären knochens - Vergleich mit Mikro-CT und biomechanischer festigkeit

Objectives: MS-CT (Multislice-Spiral-CT) has a higher spatial resolution compared to the SS-CT (Singleslice-CT). The purpose of this study was to investigate, if the higher spatial resolution of the MS-CT has advantages for structural analyses in the assessment of osteoporosis. Material and Methods: 20 cylindrical trabecular bone specimens (diameter 12 mm, length 15-20 mm) were harvested from formalin-fixed human thoracic spines. All specimens were examined by Micro-CT and quantitative, histomorphologic parameters were determined. Analogous structural parameters were calculated from the high-resolution images acquired by both MS- and SS-CT. Additionally, the BMD (bone mineral density) was measured by QCT (quantitative CT). The maximum compressive strength (MCS) was determined in a biomechanical test. The structural parameters were correlated with the histomorphologic parameters and with the MCS. Results: The parameters bone fraction and trabecular separation correlated significantly in both MS- and SS-CT with the analogous parameters from Micro-CT (r ² = 0.84, p < 0.01) and the MCS (r ² = 0.81, p < 0.01). The highest correlation with the MCS was calculated using the trabecular number measured by MS-CT in the superior region near the endplate of the vertebra with the high-resolution kernel U90 u (r ² = 0.85, p < 0.01). This correlation was significantly higher than the correlation between MCS and BMD (r ² = 0.49, p < 0.01). Conclusion: Micro-CT- and MS-CT-determined structural parameters of the trabecular bone showed significant, high correlations. Thus, a characterisation of the trabecular structure seems to be possible. The biomechanical stability of the bone can also be predicted well. The structural parameters acquired by MS-CT show higher correlations with the MCS than the BMD or structural parameters determined by SS-CT do. In this study MS-CT was best suited to predict biomechanical strength of trabecular bone.