Thomas Baum MD, Presenter: Nothing to Disclose

Felix Kopp, Abstract Co-Author: Nothing to Disclose

Radin Adi Nasirudin DIPLENG, Abstract Co-Author: Nothing to Disclose

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

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

Peter B. Noel PhD, Abstract Co-Author: Nothing to Disclose

High-resolution multi-detector computed tomography (MDCT) based trabecular bone microstructure analysis has improved the prediction of bone strength beyond bone mineral density (BMD) measurements in the context of osteoporosis. However, the clinical application of this method is currently limited due to the relatively high radiation exposure. Therefore, the purpose of our study was to investigate the effects of low-dose MDCT and iterative reconstruction algorithms on trabecular bone microstructure parameters.

Twelve thoracic vertebrae were harvested from three fresh human cadavers. MDCT imaging of each vertebra was performed in a water bath to simulate the soft tissue environment. Images were obtained by using a clinical 64-row MDCT scanner with a tube load and current of 120kV and 220mAs (full-dose protocol, FD) and 120kV and 70mAs (low-dose protocol, LD), respectively. Voxel size and slice thickness amounted to 300x300µm² and 600µm in both protocols. Images were reconstructed by using standard filtered back-projection (FBP) and in-house developed fully iterative reconstruction (IR) algorithms. BMD and trabecular bone microstructure parameters (histomorphometric parameters and fractal dimension) were determined in the MDCT images and correlated with failure load (FL) as assessed by destructive biomechanical testing of the vertebrae.

BMD significantly correlated with FL (r=0.92; p<0.05). Trabecular bone microstructure parameters showed correlations with FL in the range of r=0.84-0.94 (FD-FBP), r=0.80-0.94 (FD-IR), r=0.84-0.89 (LD-FBP), and r=0.88-0.96 (LD-IR) (p<0.05). The correlation coefficients were not significantly different (p>0.05). However, the absolute values of the trabecular bone microstructure parameters as assessed in FD-FBP, FD-IR, LD-FBP, and LD-IR were significantly different (p<0.05).

Trabecular bone microstructure parameters as assessed by low-dose MDCT and iterative reconstruction algorithms adequately predicted vertebral bone strength. However, absolute values of the microstructure parameters were dependent on the used protocol and reconstruction algorithm.

Low-dose protocols and iterative reconstruction algorithms may allow the clinical use of MDCT based trabecular bone microstructure analysis at the spine with an acceptable radiation exposure to improve fracture risk prediction and therapy monitoring in the context of osteoporosis.

Baum, T, Kopp, F, Nasirudin, R, Rummeny, E, Bauer, J, Noel, P, Trabecular Bone Microstructure Assessed by Low-dose MDCT and Iterative Reconstruction Predicts Vertebral Bone Strength.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14006731.html