Dirk Mueller MD, Presenter: Nothing to Disclose

Christoph W. Raeth PhD, Abstract Co-Author: Nothing to Disclose

Jan Stefan Bauer MD, Abstract Co-Author: Nothing to Disclose

Roberto Adrian Monetti PhD, Abstract Co-Author: Nothing to Disclose

Felix Eckstein MD, Abstract Co-Author: Co-owner, Chondrometrics GmbH Co-founder, Chondrometrics GmbH CEO, Chondrometrics GmbH Consultant, Pfizer Inc Consultant, Merck KGaA

Ernst Josef Rummeny MD, Abstract Co-Author: Nothing to Disclose

Thomas M. Link MD, Abstract Co-Author: Research grant, Merck & Co, Inc

00030490-DMT et al, Abstract Co-Author: Nothing to Disclose

In this study local filters based on wavelets (WFL) and the scaling index method (SIM) were applied to Micro-CT (µCT) images of vertebral bone specimens. These trabecular bone structure measures were compared with bone mineral density (BMD) as well as standard morphological parameters in the prediction of bone strength in vitro.

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 µCT with an isotropic resolution of 30x30x30 µm. Structure analysis was performed using mp(α), which is based on a local 3D scaling index method (SIM), as well as algorithms based on spherical Mexican hat wavelets. In addition standard morphological parameters were determined and BMD was measured by QCT (quantitative CT). All specimens were tested destructively in a biomechanical materials testing machine to determine the maximum compressive strength (MCS).

The wavelet-based texture measure (WFL) as well as mp(α) showed a significantly higher correlation with MCS (WFL: r2=0.61, mp(α): r2=0.57) than BMD (r2=0.46). WFL and mp(α) results were comparable to those obtained with histomorphometric measures (BV/TV: r2=0.45, Tr. N: r2=0.67, Tr.Sp: r2=0.67).

WFL techniques and mp(α) can successfully be applied to μCT image data of the spine. Since these two measures characterize the image structures on a local scale, they offer the possibility to identify and discriminate rods and sheets of the trabecular structure. This property may give new insights about the bone constituents responsible for the mechanical strength.

Wavelet filter techniques and nonlinear structure analysis may improve the prediction of bone strength and the risk of fracture.

Mueller, D, Raeth, C, Bauer, J, Monetti, R, Eckstein, F, Rummeny, E, Link, T, et al, 0, Three-dimensional Structure Analysis with Wavelet Filter Techniques and the Scaling Index Method to Investigate Trabecular Bone Structure in µCT Images of the Spine.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8011145.html