Annals of Biomedical Engineering

, Volume 42, Issue 5, pp 950–959

Assessment of Transverse Isotropy in Clinical-Level CT Images of Trabecular Bone Using the Gradient Structure Tensor

  • David Larsson
  • Benoît Luisier
  • Mariana E. Kersh
  • Enrico Dall’Ara
  • Philippe K. Zysset
  • Marcus G. Pandy
  • Dieter H. Pahr
Article

DOI: 10.1007/s10439-014-0983-y

Cite this article as:
Larsson, D., Luisier, B., Kersh, M.E. et al. Ann Biomed Eng (2014) 42: 950. doi:10.1007/s10439-014-0983-y

Abstract

The aim of this study was to develop a GST-based methodology for accurately measuring the degree of transverse isotropy in trabecular bone. Using femoral sub-regions scanned in high-resolution peripheral QCT (HR-pQCT) and clinical-level-resolution QCT, trabecular orientation was evaluated using the mean intercept length (MIL) and the gradient structure tensor (GST) on the HR-pQCT and QCT data, respectively. The influence of local degree of transverse isotropy (DTI) and bone mineral density (BMD) was incorporated into the investigation. In addition, a power based model was derived, rendering a 1:1 relationship between GST and MIL eigenvalues. A specific DTI threshold (DTIthres) was found for each investigated size of region of interest (ROI), above which the estimate of major trabecular direction of the GST deviated no more than 30° from the gold standard MIL in 95% of the remaining ROIs (mean error: 16°). An inverse relationship between ROI size and DTIthres was found for discrete ranges of BMD. A novel methodology has been developed, where transversal isotropic measures of trabecular bone can be obtained from clinical QCT images for a given ROI size, DTIthres and power coefficient. Including DTI may improve future clinical QCT finite-element predictions of bone strength and diagnoses of bone disease.

Keywords

Human proximal femur Structural anisotropy Clinical-level quantitative computed tomography Fabric tensors Degree of transverse isotropy 

Copyright information

© Biomedical Engineering Society 2014

Authors and Affiliations

  • David Larsson
    • 1
  • Benoît Luisier
    • 1
  • Mariana E. Kersh
    • 2
  • Enrico Dall’Ara
    • 1
  • Philippe K. Zysset
    • 3
  • Marcus G. Pandy
    • 2
  • Dieter H. Pahr
    • 1
  1. 1.Institute of Lightweight Design and Structural BiomechanicsVienna University of TechnologyViennaAustria
  2. 2.Department of Mechanical EngineeringUniversity of MelbourneParkvilleAustralia
  3. 3.Institute of Surgical Technology and BiomechanicsUniversity of BernBernSwitzerland

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