Enhanced model for predicting femoral fracture toughness in ovariectomized mice using Raman spectroscopy and x-ray imaging (Conference Presentation)

Author(s):  
Christine M. Massie ◽  
Emma Knapp ◽  
Keren Chen ◽  
Hani A. Awad ◽  
Andrew J. Berger
2013 ◽  
Vol 46 (4) ◽  
pp. 723-730 ◽  
Author(s):  
Jason A. Inzana ◽  
Jason R. Maher ◽  
Masahiko Takahata ◽  
Edward M. Schwarz ◽  
Andrew J. Berger ◽  
...  

2021 ◽  
Vol 116 ◽  
pp. 110243
Author(s):  
Christine Massie ◽  
Emma Knapp ◽  
Keren Chen ◽  
Andrew J. Berger ◽  
Hani A. Awad

2020 ◽  
Author(s):  
Christine Massie ◽  
Emma Knapp ◽  
Keren Chen ◽  
Andrew J Berger ◽  
Hani A Awad

AbstractBone fragility and fracture risk are assessed by measuring the areal bone mineral density (aBMD) using dual-energy X-ray absorptiometry (DXA). While aBMD correlates with bone strength, it is a poor predictor of fragility fracture risk. Alternatively, fracture toughness assesses the bone’s resistance to crack propagation and fracture, making it a suitable bone quality metric. Here, we explored how femoral midshaft measurements from DXA, micro-computed tomography (μCT), and Raman spectroscopy could predict fracture toughness. We hypothesized that ovariectomy (OVX) decreases aBMD and fracture toughness compared to controls and we can optimize a multivariate assessment of bone quality by combining results from X-ray and Raman spectroscopy. Female mice underwent an OVX (n=5) or sham (n=5) surgery at 3 months of age. Femurs were excised 3 months after ovariectomy and assessed with Raman spectroscopy, μCT, and DXA. Subsequently, a notch was created on the anterior side of the mid-diaphysis of the femurs. Three-point bending induced a controlled fracture that initiated at the notch. The OVX mice had a significantly lower aBMD, cortical thickness, and fracture toughness when compared to controls (p<0.05). A leave one out cross-validated (LOOCV) partial least squares regression (PLSR) model based only on the combination of aBMD and cortical thickness showed no significant predictive correlations with fracture toughness, whereas a PLSR model based on principal components derived from the full Raman spectra yielded significant prediction (r2=0.71, p<0.05). Further, the PLSR model was improved by incorporating aBMD, cortical thickness, and principal components from Raman spectra (r2=0.92, p<0.001). This exploratory study demonstrates combining X-ray with Raman spectroscopy leads to a more accurate assessment of bone fracture toughness and could be a useful diagnostic tool for the assessment of fragility fracture risk.


Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).


Author(s):  
James F. Mancuso ◽  
William B. Maxwell ◽  
Russell E. Camp ◽  
Mark H. Ellisman

The imaging requirements for 1000 line CCD camera systems include resolution, sensitivity, and field of view. In electronic camera systems these characteristics are determined primarily by the performance of the electro-optic interface. This component converts the electron image into a light image which is ultimately received by a camera sensor.Light production in the interface occurs when high energy electrons strike a phosphor or scintillator. Resolution is limited by electron scattering and absorption. For a constant resolution, more energy deposition occurs in denser phosphors (Figure 1). In this respect, high density x-ray phosphors such as Gd2O2S are better than ZnS based cathode ray tube phosphors. Scintillating fiber optics can be used instead of a discrete phosphor layer. The resolution of scintillating fiber optics that are used in x-ray imaging exceed 20 1p/mm and can be made very large. An example of a digital TEM image using a scintillating fiber optic plate is shown in Figure 2.


Author(s):  
Ann LeFurgey ◽  
Peter Ingram ◽  
J.J. Blum ◽  
M.C. Carney ◽  
L.A. Hawkey ◽  
...  

Subcellular compartments commonly identified and analyzed by high resolution electron probe x-ray microanalysis (EPXMA) include mitochondria, cytoplasm and endoplasmic or sarcoplasmic reticulum. These organelles and cell regions are of primary importance in regulation of cell ionic homeostasis. Correlative structural-functional studies, based on the static probe method of EPXMA combined with biochemical and electrophysiological techniques, have focused on the role of these organelles, for example, in maintaining cell calcium homeostasis or in control of excitation-contraction coupling. New methods of real time quantitative x-ray imaging permit simultaneous examination of multiple cell compartments, especially those areas for which both membrane transport properties and element content are less well defined, e.g. nuclei including euchromatin and heterochromatin, lysosomes, mucous granules, storage vacuoles, microvilli. Investigations currently in progress have examined the role of Zn-containing polyphosphate vacuoles in the metabolism of Leishmania major, the distribution of Na, K, S and other elements during anoxia in kidney cell nuclel and lysosomes; the content and distribution of S and Ca in mucous granules of cystic fibrosis (CF) nasal epithelia; the uptake of cationic probes by mltochondria in cultured heart ceils; and the junctional sarcoplasmic retlculum (JSR) in frog skeletal muscle.


2000 ◽  
Vol 10 (PR9) ◽  
pp. Pr9-583-Pr9-588 ◽  
Author(s):  
W. A. Gooch ◽  
M. S. Burkins ◽  
G. Hauver ◽  
P. Netherwood ◽  
R. Benck
Keyword(s):  
X Ray ◽  

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