High resolution quantitative computed tomography-based assessment of trabecular microstructure and strength estimates by finite-element analysis of the spine, but not DXA, reflects vertebral fracture status in men with glucocorticoid-induced osteoporosis

Bone ◽  
2013 ◽  
Vol 52 (2) ◽  
pp. 568-577 ◽  
Author(s):  
Christian Graeff ◽  
Fernando Marin ◽  
Helmut Petto ◽  
Ole Kayser ◽  
Andreas Reisinger ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Vertebral Fracture ◽  
High Resolution ◽  
Quantitative Computed Tomography ◽  
Element Analysis ◽  
Trabecular Microstructure

scholarly journals Effects of Scan Resolutions and Element Sizes on Bovine Vertebral Mechanical Parameters from Quantitative Computed Tomography-Based Finite Element Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Meng Zhang ◽  
Jiazi Gao ◽  
Xu Huang ◽  
He Gong ◽  
Min Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Quantitative Computed Tomography ◽  
Slice Thickness ◽  
Mechanical Parameters ◽  
Ct Scanner ◽  
Computational Accuracy ◽  
Element Analysis ◽  
Vertebral Strength

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.

scholarly journals COMPUTER AIDED THREE-DIMENSIONAL RECONSTRUCTION AND MODELING OF MIDDLE EAR BIOMECHANICS BY HIGH-RESOLUTION COMPUTED TOMOGRAPHY AND FINITE ELEMENT ANALYSIS

2006 ◽  
Vol 18 (05) ◽  
pp. 214-221 ◽  
Author(s):  
CHIA-FONE LEE ◽  
PEIR-RONG CHEN ◽  
WEN-JENG LEE ◽  
JYH-HORNG CHEN ◽  
TIEN-CHEN LIU
Keyword(s):  
Computed Tomography ◽  
Finite Element Analysis ◽  
Finite Element ◽  
High Resolution ◽  
Temporal Bone ◽  
Middle Ear ◽  
Histological Section ◽  
Slice Thickness ◽  
High Resolution Computed Tomography ◽  
Element Analysis

In order to present a systematic and practical approach that uses high-resolution computed tomography (HRCT) to derive models of the middle ear for finite element analysis (FEA). This prospective study included 31 subjects with normal hearing and no previous otological disorders. Temporal bone images obtained from 15 right ears and 16 left ears were used for evaluation and reconstruction. High-resolution computed tomography of temporal bone was performed using simultaneous acquisition of 16 sections with a collimated slice thickness of 0.625 mm. All images were transferred to an Amira visualization system for 3D reconstruction. The created 3-D model was translated into two commercial modeling packages, Patran and ANSYS, for finite element analysis. The characteristic dimensions of the model were measured and compared with previous published histological section data. This result confirms that the geometric model created by the proposed method is accurate except the tympanic membrane is thicker than that of histological section method. No obvious difference in the geometrical dimension between right and left ossicles was found (p > 0.05). The 3D model created by finite element method and predicted umbo and stapes displacements are close to the bounds of the experimental curves of Nishihara's, Huber's, and Gan's data across the frequency range of 100-8000 Hz. The model includes a description of the geometry of the middle ear components, and dynamic equations of vibration. The proposed method is quick, practical, low cost and most importantly, non-invasive as compared with histological section methods.

scholarly journals Quantitative Computed Tomography Protocols Affect Material Mapping and Quantitative Computed Tomography-Based Finite-Element Analysis Predicted Stiffness

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Hugo Giambini ◽  
Dan Dragomir-Daescu ◽  
Ahmad Nassr ◽  
Michael J. Yaszemski ◽  
Chunfeng Zhao
Keyword(s):  
Computed Tomography ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Fracture Risk ◽  
Quantitative Computed Tomography ◽  
Image Data ◽  
Element Analysis ◽  
Calibration Phantom ◽  
Fresh Frozen ◽  
Experimental Values

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.

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