Thomas Baum, Martin Gräbeldinger, Christoph Räth, Eduardo Grande Garcia, Rainer Burgkart, Janina Patsch, Ernst J. Rummeny, Thomas M. Link and Jan S. Bauer

Institut für Radiologie, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 München, Germany

Abstract:

Purpose: It was reported previously that trabecular bone structure parameters could add significant information for predicting bone strength beyond bone mineral density. In the past, trabecular bone structure analysis was limited by the spatial resolution of clinically available MDCT scanners. Recent technical improvements have made it possible to determine trabecular bone structure parameters of the spine using clinical MDCT. Therefore the purpose of this study was to assess trabecular bone structure parameters obtained from clinical MDCT as well as Xtreme-CT (hr-pQCT) as standard of reference and to investigate whether clinical MDCT can predict vertebral bone strength.

Materials and Methods: Fourteen thoracic vertebral bodies were harvested from formalin-fixed human cadavers (11 women and 3 men; age: 84±10 years). All specimens were examined using Xtreme-CT (isotropic voxel size of 41μm3) and a clinical whole-body MDCT (interpolated voxel size: 146x146x300μm3, spatial resolution: 250x250x600μm3). Trabecular bone structure analyses (histomorphometric and texture measures) were performed in the Xtreme-CT as well as MDCT images. Vertebral failure load was determined in an uniaxial biomechanical test.

Results: Xtreme-CT and MDCT derived trabecular bone structure parameters showed correlations ranging from r=0.60 to r=0.90 (p<0.001). Correlations between trabecular bone structure parameters and failure load amounted up to r=0.86 (p<0.001) using the Xtreme-CT images, and up to r=0.79 (p<0.001) using the MDCT images. Correlation coefficients obtained with Xtreme-CT and MDCT were not significantly different (p>0.05).

Conclusion: The spatial resolution of clinically available whole-body MDCT scanners is suitable for trabecular bone structure analysis of the spine and to predict vertebral bone strength.

Keywords: Osteoporosis, trabecular bone structure, Multi-Detector Computed Tomography (MDCT), high-resolution peripheral Quantitative Computed Tomography (hr-pQCT).