Holger Boehm MD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: to predict the mechanical strength of human spinal and femoral bone specimens in vitro by structural analysis of high resolution magnetic resonance images (HRMRI) using non-linear measures based on the Minkowski Functionals in 2D and to compare the results with bone mineral density (BMD) as measured by quantitative computed tomography (QCT) and standard linear morphometric measures. Methods and Materials: For 34 human femoral and 11 spinal bone specimens axial HRMR images with a voxel-size of 117x156x300 μm3 were obtained using a 3D-gradient-echo-sequence. BMD was measured by QCT. After imaging all specimens were tested destructively for maximum compressive strength (MCS). From the spectra of the three Minkowski Functionals (MF) that completely describe the topology of the image slices a number of characteristic parameters such as maximum / minimum values, zero-crossing, slope, etc. were computed. In addition, standard morphometric parameters in 2D (apparent bone fraction {app.BV/TV}, apparent trabecular spacing {app.Tb.Sp}) were obtained from these images. Results: R2 for MCS vs. the parameters based on the MF ranged from 0.58 to 0.71 (p<0.001) which was of comparable magnitude as MCS vs. BMD (R2 = 0.72, p<0.001) and considerably higher than MCS vs. the linear morphometric measures with R2 ranging from 0.3 to 0.38 (p = 0.05). The predictive performance of the MF-based measures was better in the spinal (R2 ranging from 0.5 to 0.81, p=0.001) than in the femoral specimens (R2 ranging from 0.3 to 0.58, p=0.001) while R2 for MCS vs. BMD was 0.76 (p = 0.001) for the femoral and R2 = 0.5 (p = 0.001) for the spinal specimens. No significant variation with anatomic origin was observed for the standard morphometric measures where best results were obtained for app.Tb.Sp. with R2 = 0.4 and 0.42, respectively. Conclusion: The results of our study show that structural parameters extracted from HRMRI by algorithms considering topological properties expressed in terms of Minkowski Functionals can effectively be used to predict the mechanical properties of trabecular bone in vitro. The predictive performance is better than that of linear measures and, depending on the anatomic origin comparable or better than BMD.       Questions about this event email: boehm@roe.med.tu-muenchen.de

Boehm MD, H, Predicting the Mechanical Strength of Human Trabecular Bone Specimens in Vitro by Application of Non-linear Structural Parameters based on Topological Properties (Minkowski Functionals) to High-Resolution Magnetic Resonance Images.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3100400.html