Effects of Once-Monthly Oral Ibandronate on Lumbar Spine Bone Strength and Quality Assessed by Volumetric Quantitative Computed Tomography and Finite Element Analysis

2008 ◽  
Vol 11 (3) ◽  
pp. 448-449
Author(s):  
E. Michael Lewiecki ◽  
T.M. Keaveny ◽  
H.K. Genant ◽  
K. Engelke ◽  
M.B. Enslin ◽  
...  
2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Meng Zhang ◽  
Jiazi Gao ◽  
Xu Huang ◽  
He Gong ◽  
Min Zhang ◽  
...  

Quantitative computed tomography-based finite element analysis (QCT/FEA) has been developed to predict vertebral strength. However, QCT/FEA models may be different with scan resolutions and element sizes. The aim of this study was to explore the effects of scan resolutions and element sizes on QCT/FEA outcomes. Nine bovine vertebral bodies were scanned using the clinical CT scanner and reconstructed from datasets with the two-slice thickness, that is, 0.6 mm (PA resolution) and 1 mm (PB resolution). There were significantly linear correlations between the predicted and measured principal strains (R2>0.7, P<0.0001), and the predicted vertebral strength and stiffness were modestly correlated with the experimental values (R2>0.6, P<0.05). Two different resolutions and six different element sizes were combined in pairs, and finite element (FE) models of bovine vertebral cancellous bones in the 12 cases were obtained. It showed that the mechanical parameters of FE models with the PB resolution were similar to those with the PA resolution. The computational accuracy of FE models with the element sizes of 0.41 × 0.41 × 0.6 mm3 and 0.41 × 0.41 × 1 mm3 was higher by comparing the apparent elastic modulus and yield strength. Therefore, scan resolution and element size should be chosen optimally to improve the accuracy of QCT/FEA.


2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Hugo Giambini ◽  
Dan Dragomir-Daescu ◽  
Ahmad Nassr ◽  
Michael J. Yaszemski ◽  
Chunfeng Zhao

Quantitative computed tomography-based finite-element analysis (QCT/FEA) has become increasingly popular in an attempt to understand and possibly reduce vertebral fracture risk. It is known that scanning acquisition settings affect Hounsfield units (HU) of the CT voxels. Material properties assignments in QCT/FEA, relating HU to Young's modulus, are performed by applying empirical equations. The purpose of this study was to evaluate the effect of QCT scanning protocols on predicted stiffness values from finite-element models. One fresh frozen cadaveric torso and a QCT calibration phantom were scanned six times varying voltage and current and reconstructed to obtain a total of 12 sets of images. Five vertebrae from the torso were experimentally tested to obtain stiffness values. QCT/FEA models of the five vertebrae were developed for the 12 image data resulting in a total of 60 models. Predicted stiffness was compared to the experimental values. The highest percent difference in stiffness was approximately 480% (80 kVp, 110 mAs, U70), while the lowest outcome was ∼1% (80 kVp, 110 mAs, U30). There was a clear distinction between reconstruction kernels in predicted outcomes, whereas voltage did not present a clear influence on results. The potential of QCT/FEA as an improvement to conventional fracture risk prediction tools is well established. However, it is important to establish research protocols that can lead to results that can be translated to the clinical setting.


Sign in / Sign up

Export Citation Format

Share Document