Monitoring individual morphological changes over time in ovariectomized rats by in vivo micro-computed tomography

Bone ◽  
2006 ◽  
Vol 39 (4) ◽  
pp. 854-862 ◽  
Author(s):  
Steven K. Boyd ◽  
Peter Davison ◽  
Ralph Müller ◽  
Jürg A. Gasser
Keyword(s):  
Computed Tomography ◽  
Morphological Changes ◽  
Ovariectomized Rats ◽  
Micro Computed Tomography ◽  
Changes Over Time ◽  
Over Time

scholarly journals P268 SUBCHONDRAL BONE PLATE REMODELING IN OSTEOARTHRITIS FOLLOWED OVER TIME BY IN VIVO MICRO-COMPUTED TOMOGRAPHY

2006 ◽  
Vol 14 ◽  
pp. S145-S146
Author(s):  
S.M. Botter ◽  
Y.H. Sniekers ◽  
J.H. Waarsing ◽  
G.J. van Osch ◽  
J.A. Verhaar ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Subchondral Bone ◽  
Bone Plate ◽  
Subchondral Bone Plate ◽  
Micro Computed Tomography ◽  
Over Time

Micro-Computed Tomography to Finite Element Analysis of In Vivo Biodegradable Magnesium-Alloy Screw and Surrounding Bone in Rabbit Femurs

2015 ◽  
Author(s):  
Adrienne F. O. Williams ◽  
Matthew B. A. McCullough
Keyword(s):  
Computed Tomography ◽  
Finite Element ◽  
Mg Alloy ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Element Analysis ◽  
Animal Modeling ◽  
Finite Element Software ◽  
Over Time

Magnesium (Mg) and its alloys are attractive orthopedic biomaterials because of their degradability and mechanical properties, which are similar to bone’s. Characterizing the mechanical changes and interactions of these promising degradable biomaterials and the host environment (bone) is essential to their success in orthopedic devices. The objective of this study was to develop a protocol to evaluate in vivo biodegradable Mg-alloy screws and surrounding new and cancellous bone in rabbit femurs over time, using high resolution micro-computed tomography (micro-CT) images and the finite element method. Micro-CT was used to visually evaluate bone remodeling and degradation of Mg-alloy screws that were implanted in rabbit femoral condyles for 2, 4, 12, 24, 36 and 52 weeks. Over time, the degradation product around the device and the remainder of the intact core was observed. Scans were segmented into bone, degradation/corrosion products and non-degraded device, then reconstructed into 3D volumes. These volumes were meshed and assigned material properties based on CT data. The meshed volumes were exported to finite element software and analyzed in a virtual environment. Several foundational observations were made about animal modeling of in vivo degrading magnesium devices with a micro-CT to FEA protocol.

scholarly journals Longitudinal Imaging of Liver Cancer Using MicroCT and Nanoparticle Contrast Agents in CRISPR/Cas9-Induced Liver Cancer Mouse Model

2021 ◽  
Vol 20 ◽  
pp. 153303382110164
Author(s):  
Sang Bu An ◽  
Kwangmo Yang ◽  
Chang Won Kim ◽  
Si Ho Choi ◽  
Eunji Kim ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Liver Cancer ◽  
Contrast Agents ◽  
Kupffer Cells ◽  
Micro Computed Tomography ◽  
Hepatic Parenchyma ◽  
Heterogeneous Distribution ◽  
Computed Tomography Images ◽  
Longitudinal Imaging ◽  
Over Time

Introduction: Micro-computed tomography with nanoparticle contrast agents may be a suitable tool for monitoring the time course of the development and progression of tumors. Here, we suggest a practical and convenient experimental method for generating and longitudinally imaging murine liver cancer models. Methods: Liver cancer was induced in 6 experimental mice by injecting clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated protein 9 plasmids causing mutations in genes expressed by hepatocytes. Nanoparticle agents are captured by Kupffer cells and detected by micro-computed tomography, thereby enabling longitudinal imaging. A total of 9 mice were used for the experiment. Six mice were injected with both plasmids and contrast, 2 injected with contrast alone, and one not injected with either agent. Micro-computed tomography images were acquired every 2- up to 14-weeks after cancer induction. Results: Liver cancer was first detected by micro-computed tomography at 8 weeks. The mean value of hepatic parenchymal attenuation remained almost unchanged over time, although the standard deviation of attenuation, reflecting heterogeneous contrast enhancement of the hepatic parenchyma, increased slowly over time in all mice. Histopathologically, heterogeneous distribution and aggregation of Kupffer cells was more prominent in the experimental group than in the control group. Heterogeneous enhancement of hepatic parenchyma, which could cause image quality deterioration and image misinterpretation, was observed and could be due to variation in Kupffer cells distribution. Conclusion: Micro-computed tomography with nanoparticle contrast is useful in evaluating the induction and characteristics of liver cancer, determining appropriate size of liver cancer for testing, and confirming therapeutic response.

Abstract 452: Longitudinal Visualization of Calcification Genesis and Growth in vivo : Novel Implications for Plaque Vulnerability

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Joshua D Hutcheson ◽  
Claudia Goettsch ◽  
Brett Pieper ◽  
Tan Pham ◽  
Jung Choi ◽  
...  
Keyword(s):  
Cardiovascular Risk ◽  
Aortic Root ◽  
Atherogenic Diet ◽  
Alizarin Red S ◽  
Arterial Calcification ◽  
Micro Computed Tomography ◽  
Alizarin Red ◽  
Histological Sections ◽  
Over Time

Background: Clinical evidence links arterial calcification and cardiovascular risk. Fibrous cap microcalcifications can promote atherosclerotic plaque failure, and large calcifications can stabilize the plaque. Therefore, calcification morphology can determine cardiovascular morbidity, but temporal patterns of calcific mineral deposition and growth remain unknown. Results: Apolipoprotein E-deficient ( Apoe-/- ) mice on an atherogenic diet develop plaque calcification. Longitudinal studies were performed using two different fluorescent calcium tracers injected intravenously into Apoe-/- mice: calcein injection following 18 weeks of atherogenic diet (n=7) and alizarin red S injection into the same mice 1 (n=4) or 3 (n=3) weeks later. Imaging green (calcein) and red (alizarin red S) fluorescence provided snapshots of aortic calcification at 18, 19, and 21 weeks. Observations within histological sections revealed green microcalcifications at 18 weeks embedded within alizarin red stained larger calcifications that were formed by 19 weeks (a). These data demonstrate that microcalcifications present at the start of calcification become the core of the larger calcifications that develop over time. Serial histological sections from aortic root to arch (b) were digitally reconstructed into 3D volumes (c) to reveal total calcific burden and localization within the aortic wall (d). Total calcification volume increased at a significant rate of 6.0x10 6 μm 3 per week (R 2 =0.99, p=0.007) and progressed from aortic arch to aortic root over time (p<0.001). Observations closely match calcification morphologies found by micro-computed tomography of human coronary arteries. Conclusion: Temporal and spatial understanding arterial calcification growth is crucial given the link between mineral morphology and cardiovascular risk, and these techniques provide a method for testing therapeutic approaches to control calcification morphology over time in situ .

scholarly journals Estrogen modulates the recruitment of myelopoietic cell progenitors in rat through a stromal cell-independent mechanism involving apoptosis

Blood ◽  
1996 ◽  
Vol 87 (7) ◽  
pp. 2683-2692 ◽  
Author(s):  
NK Shevde ◽  
JW Pike
Keyword(s):  
Estrogen Receptor ◽  
Ovarian Function ◽  
Morphological Changes ◽  
Estrogen Treatment ◽  
Ovariectomized Rats ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Protective Effects ◽  
Hematopoietic Stem

Loss of ovarian function leads to a significant increase in the number of bone-resorbing osteoclasts. Estrogen replacement is known to manifest bone protective effects in the treatment of postmenopausal osteoporosis. In the present study, we used ovariectomized rats to examine the effects of estrogen loss at the osteoclast progenitor colony forming unit-granulocyte macrophage (CFU-GM) level. A significant increase in CFU-GM number was observed as early as 7 days following ovariectomy, and correlated directly with an increase in the number of osteoclast-like cells generated in marrow cultures. The increase in CFU-GM following ovariectomy was abrogated in animals that received estrogen treatment in vivo. A similar suppressive effect was observed on CFU-GM number when ovariectomized rat marrow was treated with estrogen in vitro. This effect was blocked in the presence of the estrogen antihormone ICI 164,384. Thus, the data suggest the possibility that estrogen exerts a direct effect on osteoclast progenitors, and does so through the estrogen receptor-mediated mechanism. Ovariectomy also led to an increase in the early hematopoietic stem/progenitor cell population (Thy 1.1+ cells) as determined by FLOW cytometry methods. Morphological changes as well as terminal deoxynucleotidyl transferase assays revealed that estrogen treatment negated growth factor-induced proliferation of these early progenitors by promoting apoptosis. The cellular effects of estrogen in vitro together with the immunocytochemical detection of the estrogen receptor in these cells, strongly support the contention that in addition to osteoclast progenitors such as CFU-GM, earlier hematopoietic progenitors are also unique cellular targets for estrogen action.

scholarly journals Feasibility of a Modified Biopsy Needle for Irreversible Electroporation Ablation and Periprocedural Tissue Sampling

2016 ◽  
Vol 15 (6) ◽  
pp. 749-758 ◽  
Author(s):  
Thomas Wimmer ◽  
Govindarajan Srimathveeravalli ◽  
Mikhail Silk ◽  
Sebastien Monette ◽  
Narendra Gutta ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Core Biopsy ◽  
Morphological Changes ◽  
Irreversible Electroporation ◽  
Tissue Sampling ◽  
Ablation Zone ◽  
Biopsy Needle ◽  
Similar Shape ◽  
Biopsy Needles

Objectives: To test the feasibility of modified biopsy needles as probes for irreversible electroporation ablation and periprocedural biopsy. Methods: Core biopsy needles of 16-G/9-cm were customized to serve as experimental ablation probes. Computed tomography-guided percutaneous irreversible electroporation was performed in in vivo porcine kidneys with pairs of experimental (n = 10) or standard probes (n = 10) using a single parameter set (1667 V/cm, ninety 100 µs pulses). Two biopsy samples were taken immediately following ablation using the experimental probes (n = 20). Ablation outcomes were compared using computed tomography, simulation, and histology. Biopsy and necropsy histology were compared. Results: Simulation-suggested ablations with experimental probes were smaller than that with standard electrodes (455.23 vs 543.16 mm2), although both exhibited similar shape. Computed tomography (standard: 556 ± 61 mm2, experimental: 515 ± 67 mm2; P = .25) and histology (standard: 313 ± 77 mm2, experimental: 275 ± 75 mm2; P = .29) indicated ablations with experimental probes were not significantly different from the standard. Histopathology indicated similar morphological changes in both groups. Biopsies from the ablation zone yielded at least 1 core with sufficient tissue for analysis (11 of the 20). Conclusions: A combined probe for irreversible electroporation ablation and periprocedural tissue sampling from the ablation zone is feasible. Ablation outcomes are comparable to those of standard electrodes.

Demineralized bone matrix-based microcarrier scaffold favors vascularized large bone regeneration in vivo in a rat model

2018 ◽  
Vol 33 (2) ◽  
pp. 182-195 ◽  
Author(s):  
Qiannan Li ◽  
Wenjie Zhang ◽  
Guangdong Zhou ◽  
Yilin Cao ◽  
Wei Liu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Stem Cells ◽  
Bone Marrow ◽  
Bone Regeneration ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Matrix Group ◽  
Micro Computed Tomography ◽  
Demineralized Bone

Insufficient neo-vascularization of in vivo implanted cell-seeded scaffold remains a major bottleneck for clinical translation of engineered bone formation. Demineralized bone matrix is an ideal bone scaffold for bone engineering due to its structural and biochemical components similar to those of native bone. We hypothesized that the microcarrier form of demineralized bone matrix favors ingrowth of vessels and bone regeneration upon in vivo implantation. In this study, a rat model of femoral vessel pedicle-based bone engineering was employed by filling the demineralized bone matrix scaffolds inside a silicone chamber that surrounded the vessel pedicles, and to compare the efficiency of vascularized bone regeneration between microcarrier demineralized bone matrix and block demineralized bone matrix. The results showed that bone marrow stem cells better adhered to microcarrier demineralized bone matrix and produced more extracellular matrices during in vitro culture. After in vivo implantation, microcarrier demineralized bone matrix seeded with bone marrow stem cells formed relatively more bone tissue than block demineralized bone matrix counterpart at three months upon histological examination. Furthermore, micro-computed tomography three-dimensional reconstruction showed that microcarrier demineralized bone matrix group regenerate significantly better and more bone tissues than block demineralized bone matrix both qualitatively and quantitatively (p < 0.05). Moreover, micro-computed tomography reconstructed angiographic images also demonstrated significantly enhanced tissue vascularization in microcarrier demineralized bone matrix group than in block demineralized bone matrix group both qualitatively and quantitatively (p < 0.05). Anti-CD31 immunohistochemical staining of (micro-) vessels and semi-quantitative analysis also evidenced enhanced vascularization of regenerated bone in microcarrier demineralized bone matrix group than in block demineralized bone matrix group (p < 0.05). In conclusion, the microcarrier form of demineralized bone matrix is an ideal bone regenerative scaffold due to its advantages of osteoinductivity and vascular induction, two essentials for in vivo bone regeneration.

scholarly journals A pancreatic mucinous cystic neoplasm undergoing intriguing morphological changes over time and associated with recurrent pancreatitis

Medicine ◽  
2019 ◽  
Vol 98 (28) ◽  
pp. e16435 ◽  
Author(s):  
Erika Shioyama ◽  
Akira Mitoro ◽  
Hiroyuki Ogawa ◽  
Takuya Kubo ◽  
Takahiro Ozutsumi ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Mucinous Cystic Neoplasm ◽  
Cystic Neoplasm ◽  
Recurrent Pancreatitis ◽  
Changes Over Time ◽  
Over Time
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