Airway and pulmonary vascular measurements using contrast-enhanced micro-CT in rodents

2013 ◽  
Vol 304 (12) ◽  
pp. L831-L843 ◽  
Author(s):  
W. B. Counter ◽  
I. Q. Wang ◽  
T. H. Farncombe ◽  
N. R. Labiris
Keyword(s):  
Structural Information ◽  
Small Animal ◽  
Pulmonary Vasculature ◽  
Detailed Knowledge ◽  
Micro Ct ◽  
Imaging Data ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Drug Deposition ◽  
Contrast Enhanced

Preclinical imaging allows pulmonary researchers to study lung disease and pulmonary drug delivery noninvasively and longitudinally in small animals. However, anatomically localizing a pathology or drug deposition to a particular lung region is not easily done. Thus, a detailed knowledge of the anatomical structure of small animal lungs is necessary for understanding disease progression and in addition would facilitate the analysis of the imaging data, mapping drug deposition and relating function to structure. In this study, contrast-enhanced micro-computed tomography (CT) of the lung produced high-resolution images that allowed for the characterization of the rodent airway and pulmonary vasculature. Contrast-enhanced micro-CT was used to visualize the airways and pulmonary vasculature in Sprague-Dawley rats (200–225 g) and BALB/c mice (20–25 g) postmortem. Segmented volumes from these images were processed to yield automated measurements of the airways and pulmonary vasculature. The diameters, lengths, and branching angles of the airway, arterial, and venous trees were measured and analyzed as a function of generation number and vessel diameter to establish rules that could be applied at all levels of tree hierarchy. In the rat, airway, arterial, and venous tress were measured down to the 20th, 16th, and 14th generation, respectively. In the mouse, airway, arterial, and venous trees were measured down to the 16th, 8th, and 7th generation, respectively. This structural information, catalogued in a rodent database, will increase our understanding of lung structure and will aid in future studies of the relationship between structure and function in animal models of disease.

scholarly journals Cutting-edge microangio-CT: new dimensions in vascular imaging and kidney morphometry

2018 ◽  
Vol 314 (3) ◽  
pp. F493-F499 ◽  
Author(s):  
Ruslan Hlushchuk ◽  
Cédric Zubler ◽  
Sébastien Barré ◽  
Carlos Correa Shokiche ◽  
Laura Schaad ◽  
...  
Keyword(s):  
Data Sets ◽  
Micro Ct ◽  
Quantitative Methodology ◽  
Micro Computed Tomography ◽  
Qualitative And Quantitative ◽  
Correlative Imaging ◽  
Contrast Enhanced ◽  
Consistent Assessment ◽  
Definition Of ◽  
X Ray Absorption

In the last decades, the contrast-enhanced micro-computed tomography (micro-CT) imaging of a whole animal kidney became increasingly important. The visualization was mainly limited to middle-sized vessels. Since modern desktop micro-CT scanners provide the necessary detail resolution, we developed an approach for rapid visualization and consistent assessment of kidney vasculature and glomeruli number. This method is based on μAngiofil, a new polymerizing contrast agent with homogenous X-ray absorption, which provides continuous filling of the complete vasculature and enables correlative imaging approaches. For rapid and reliable kidney morphometry, the microangio-CT (µaCT) data sets from glial cell line-derived neurotrophic factor (GDNF)+/− mice and their wild-type littermates were used. The results were obtained much faster compared with the current gold standard, histology-based stereology, and without processing artifacts. The histology-based morphometry was done afterward on the same kidneys. Both approaches revealed that the GDNF+/− male mice had about 40% fewer glomeruli. Furthermore, our approach allows for the definition of sites of interest for further histological investigation, i.e., correlative morphology. The polymerized μAngiofil stays in perfused vessels and is autofluorescent, which is what greatly facilitates the matching of histological sections with µaCT data. The presented approach is a time-efficient, reliable, qualitative, and quantitative methodology. Besides glomerular morphometry, the µaCT data can be used for qualitative and quantitative analysis of the kidney vasculature and correlative morphology.

scholarly journals Experimental study of the effects of hypoxia simulator on osteointegration of titanium prosthesis in osteoporotic rats

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jiangfeng Liu ◽  
Huijun Kang ◽  
Jiangfeng Lu ◽  
Yike Dai ◽  
Fei Wang
Keyword(s):  
Signaling Pathway ◽  
Control Group ◽  
Osteoporotic Bone ◽  
Sham Operation ◽  
Mrna Levels ◽  
Micro Ct ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Sham Operation Group ◽  
Pull Out

Abstract Background Poor osseointegration is the key reason for implant failure after arthroplasty,whether under osteoporotic or normal bone conditions. To date, osseointegration remains a major challenge. Recent studies have shown that deferoxamine (DFO) can accelerate osteogenesis by activating the hypoxia signaling pathway. The purpose of this study was to test the following hypothesis: after knee replacement, intra-articular injection of DFO will promote osteogenesis and osseointegration with a 3D printed titanium prosthesis in the bones of osteoporotic rats. Materials and methods Ninety female Sprague–Dawley rats were used for the experiment. Ten rats were used to confirm the successful establishment of the osteoporosis model: five rats in the sham operation group and five rats in the ovariectomy group. After ovariectomy and knee arthroplasty were performed, the remaining 80 rats were randomly divided into DFO and control groups (n = 40 per group). The two groups were treated by intraarticular injection of DFO and saline respectively. After 2 weeks, polymerase chain reaction (PCR) and immunohistochemistry were used to evaluate the levels of HIF-1a, VEGF, and CD31. HIF-1a and VEGF have been shown to promote angiogenesis and bone regeneration, and CD31 is an important marker of angiogenesis. After 12 weeks, the specimens were examined by micro-computed tomography (micro-CT), biomechanics, and histopathology to evaluate osteogenesis and osseointegration. Results The results of PCR showed that the mRNA levels of VEGF and CD31 in the DFO group were significantly higher than those in the control group. The immunohistochemistry results indicated that positive cell expression of HIF-1a, VEGF, and CD31 in the DFO group was also higher. Compared with the control group, the micro-CT parameters of BMD, BV/TV, TB. N, and TB. Th were significantly higher. The maximal pull-out force and the bone-to-implant contact value were also higher. Conclusions The local administration of DFO, which is used to activate the HIF-1a signaling pathway, can promote osteogenesis and osseointegration with a prosthesis in osteoporotic bone.

scholarly journals Development of a bent Laue beam-expanding double-crystal monochromator for biomedical X-ray imaging

2014 ◽  
Vol 21 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Mercedes Martinson ◽  
Nazanin Samadi ◽  
George Belev ◽  
Bassey Bassey ◽  
Rob Lewis ◽  
...  
Keyword(s):  
Beam Quality ◽  
Dynamic Imaging ◽  
Micro Ct ◽  
Imaging Data ◽  
Micro Computed Tomography ◽  
Double Crystal ◽  
Double Crystal Monochromator ◽  
X Ray Imaging ◽  
Beam Expander ◽  
Vertical Beam

The Biomedical Imaging and Therapy (BMIT) beamline at the Canadian Light Source has produced some excellent biological imaging data. However, the disadvantage of a small vertical beam limits its usability in some applications. Micro-computed tomography (micro-CT) imaging requires multiple scans to produce a full projection, and certain dynamic imaging experiments are not possible. A larger vertical beam is desirable. It was cost-prohibitive to build a longer beamline that would have produced a large vertical beam. Instead, it was proposed to develop a beam expander that would create a beam appearing to originate at a source much farther away. This was accomplished using a bent Laue double-crystal monochromator in a non-dispersive divergent geometry. The design and implementation of this beam expander is presented along with results from the micro-CT and dynamic imaging tests conducted with this beam. Flux (photons per unit area per unit time) has been measured and found to be comparable with the existing flat Bragg double-crystal monochromator in use at BMIT. This increase in overall photon count is due to the enhanced bandwidth of the bent Laue configuration. Whilst the expanded beam quality is suitable for dynamic imaging and micro-CT, further work is required to improve its phase and coherence properties.

scholarly journals Radiomorphometric Quantitative Analysis of Vasculature Utilizing Micro–Computed Tomography and Vessel Perfusion in the Murine Mandible

2012 ◽  
Vol 5 (4) ◽  
pp. 223-229 ◽  
Author(s):  
Xi Lin Jing ◽  
Aaron S. Farberg ◽  
Laura A. Monson ◽  
Alexis Donneys ◽  
Catherine N. Tchanque-Fossuo ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Quantitative Measure ◽  
Micro Ct ◽  
Vascular Networks ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Craniofacial Skeleton ◽  
Sprague Dawley Rats ◽  
Quantitative Data Analysis

Purpose Biomechanical, densitometric, and histological analyses have been the mainstay for reproducible outcome measures for investigation of new bone formation and osseous healing. Here we report the addition of radiomorphometric vascular analysis as a quantitative measure of vascularity in the murine mandible. To our knowledge this is the first description of using micro–computed tomography (micro-CT) to evaluate the temporal and spatial pattern of angiogenesis in the craniofacial skeleton. Methods The vessel perfusion technique was performed on 10 Sprague-Dawley rats using Microfil (MV-122, Flow Tech; Carver, MA). After decalcification, hemimandibles were imaged using high-resolution micro-CT. Six separate radiomorphometric vascular metrics were calculated. Results Radiomorphometric values were analyzed using three different thresholds on micro-CT. Experimentally, 1000 Hounsfield units was found to be the optimal threshold for analysis to capture the maximal vascular content of the bone. Data from seven hemimandibles were analyzed. Minimal statistical variance in each of the quantitative measures of vascularity resulted in reproducible metrics for each of the radiomorphometric parameters. Conclusions We have demonstrated that micro-CT vascular imaging provides a robust methodology for evaluation of vascular networks in the craniofacial skeleton. This technique provides 3D quantitative data analysis that differs significantly from laser Doppler and microsphere methods, which simply measure flow. This technique is advantageous over labor-intensive 2D conventional analyses using histology and X-ray microangiography. Our data establish the appropriate thresholding for optimal vascular analyses and provide baseline measurements that can be used to analyze the role of angiogenesis in bone regeneration and repair in the craniofacial skeleton.

scholarly journals A Single Axial Impact Load Causes Articular Damage That Is Not Visible with Micro-Computed Tomography: An Ex Vivo Study on Caprine Tibiotalar Joints

Cartilage ◽  
2019 ◽  
pp. 194760351987635 ◽  
Author(s):  
Robin P. Blom ◽  
Douwe Mol ◽  
Leo J. van Ruijven ◽  
Gino M. M. J. Kerkhoffs ◽  
Theo H. Smit
Keyword(s):  
Articular Cartilage ◽  
High Resolution ◽  
Ex Vivo ◽  
Impact Loads ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Axial Impact ◽  
Tibiotalar Joint ◽  
Articular Fractures ◽  
Contrast Enhanced

Objective Excessive articular loading, for example, an ankle sprain, may result in focal osteochondral damage, initiating a vicious degenerative process resulting in posttraumatic osteoarthritis (PTOA). Better understanding of this degenerative process would allow improving posttraumatic care with the aim to prevent PTOA. The primary objective of this study was to establish a drop-weight impact testing model with controllable, reproducible and quantitative axial impact loads to induce osteochondral damage in caprine tibiotalar joints. We aimed to induce osteochondral damage on microscale level of the tibiotalar joint without gross intra-articular fractures of the tibial plafond. Design Fresh-frozen tibiotalar joints of mature goats were used as ex vivo articulating joint models. Specimens were axially impacted by a mass of 10.5 kg dropped from a height of 0.3 m, resulting in a speed of 2.4 m/s, an impact energy of 31.1 J and an impact impulse of 25.6 N·s. Potential osteochondral damage of the caprine tibiotalar joints was assessed using contrast-enhanced high-resolution micro-computed tomography (micro-CT). Subsequently, we performed quasi-static loading experiments to determine postimpact mechanical behavior of the tibiotalar joints. Results Single axial impact loads with a mass of 15.5 kg dropped from 0.3 m, resulted in intra-articular fractures of the tibial plafond, where a mass of 10.55 kg dropped from 0.3 m did not result in any macroscopic damage. In addition, contrast-enhanced high-resolution micro-CT imaging neither reveal any acute microdamage (i.e., microcracks) of the subchondral bone nor any (micro)structural changes in articular cartilage. The Hexabrix content or voxel density (i.e., proteoglycan content of the articular cartilage) on micro-CT did not show any differences between intact and impacted specimens. However, quasi-static whole-tibiotalar-joint loading showed an altered biomechanical behavior after application of a single axial impact (i.e., increased hysteresis when compared with the intact or nonimpacted specimens). Conclusions Single axial impact loads did not induce osteochondral damage visible with high-resolution contrast-enhanced micro-CT. However, despite the lack of damage on macro- and even microscale, the single axial impact loads resulted in “invisible injuries” because of the observed changes in the whole-joint biomechanics of the caprine tibiotalar joints. Future research must focus on diagnostic tools for the detection of early changes in articular cartilage after a traumatic impact (i.e., ankle sprains or ankle fractures), as it is well known that this could result in PTOA.

scholarly journals Deferoxamine Reduces Inflammation and Osteoclastogenesis in Avulsed Teeth

2021 ◽  
Vol 22 (15) ◽  
pp. 8225
Author(s):  
Ko Eun Lee ◽  
Mijeong Jeon ◽  
Seunghan Mo ◽  
Hyo-Seol Lee ◽  
Je Seon Song ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Alveolar Bone ◽  
Root Surface ◽  
Tartrate Resistant Acid Phosphatase ◽  
Micro Ct ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Model Cell

Replacement and inflammatory resorption are serious complications associated with the delayed replantation of avulsed teeth. In this study, we aimed to assess whether deferoxamine (DFO) can suppress inflammation and osteoclastogenesis in vitro and attenuate inflammation and bone resorption in a replanted rat tooth model. Cell viability and inflammation were evaluated in RAW264.7 cells. Osteoclastogenesis was confirmed by tartrate-resistant acid phosphatase staining, reactive oxygen species (ROS) measurement, and quantitative reverse transcriptase–polymerase chain reaction in teeth exposed to different concentrations of DFO. In vivo, molars of 31 six-week-old male Sprague–Dawley rats were extracted and stored in saline (n = 10) or DFO solution (n = 21) before replantation. Micro-computed tomography (micro-CT) imaging and histological analysis were performed to evaluate inflammation and root and alveolar bone resorption. DFO downregulated the genes related to inflammation and osteoclastogenesis. DFO also reduced ROS production and regulated specific pathways. Furthermore, the results of the micro-CT and histological analyses provided evidence of the decrease in inflammation and hard tissue resorption in the DFO group. Overall, these results suggest that DFO reduces inflammation and osteoclastogenesis in a tooth replantation model, and thus, it has to be further investigated as a root surface treatment option for an avulsed tooth.

scholarly journals Erbium-Based Perfusion Contrast Agent for Small-Animal Microvessel Imaging

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Justin J. Tse ◽  
P. Joy Dunmore-Buyze ◽  
Maria Drangova ◽  
David W. Holdsworth
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Spectral Band ◽  
Small Animal ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Preclinical Research ◽  
X Ray ◽  
Tissue Specimens ◽  
X Ray Absorption

Micro-computed tomography (micro-CT) facilitates the visualization and quantification of contrast-enhanced microvessels within intact tissue specimens, but conventional preclinical vascular contrast agents may be inadequate near dense tissue (such as bone). Typical lead-based contrast agents do not exhibit optimal X-ray absorption properties when used with X-ray tube potentials below 90 kilo-electron volts (keV). We have developed a high-atomic number lanthanide (erbium) contrast agent, with a K-edge at 57.5 keV. This approach optimizes X-ray absorption in the output spectral band of conventional microfocal spot X-ray tubes. Erbium oxide nanoparticles (nominal diameter < 50 nm) suspended in a two-part silicone elastomer produce a perfusable fluid with viscosity of 19.2 mPa-s. Ultrasonic cavitation was used to reduce aggregate sizes to <70 nm. Postmortem intact mice were perfused to investigate the efficacy of contrast agent. The observed vessel contrast was >4000 Hounsfield units, and perfusion of vessels < 10 μm in diameter was demonstrated in kidney glomeruli. The described new contrast agent facilitated the visualization and quantification of vessel density and microarchitecture, even adjacent to dense bone. Erbium’s K-edge makes this contrast agent ideally suited for both single- and dual-energy micro-CT, expanding potential preclinical research applications in models of musculoskeletal, oncological, cardiovascular, and neurovascular diseases.

scholarly journals Quantitative Imaging Parameters of Contrast-Enhanced Micro-Computed Tomography Correlate with Angiogenesis and Necrosis in a Subcutaneous C6 Glioma Model

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3417
Author(s):  
Lízbeth Ayala-Domínguez ◽  
Enrique Pérez-Cárdenas ◽  
Alejandro Avilés-Salas ◽  
Luis Alberto Medina ◽  
Marcela Lizano ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Quantitative Imaging ◽  
C6 Glioma ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Imaging Parameters ◽  
Dynamic Contrast Enhanced ◽  
Tumor Periphery ◽  
Contrast Enhanced ◽  
Glioma Model

The aim of this work was to systematically obtain quantitative imaging parameters with static and dynamic contrast-enhanced (CE) X-ray imaging techniques and to evaluate their correlation with histological biomarkers of angiogenesis in a subcutaneous C6 glioma model. Enhancement (E), iodine concentration (CI), and relative blood volume (rBV) were quantified from single- and dual-energy (SE and DE, respectively) micro-computed tomography (micro-CT) images, while rBV and volume transfer constant (Ktrans) were quantified from dynamic contrast-enhanced (DCE) planar images. CI and rBV allowed a better discernment of tumor regions from muscle than E in SE and DE images, while no significant differences were found for rBV and Ktrans in DCE images. An agreement was found in rBV for muscle quantified with the different imaging protocols, and in CI and E quantified with SE and DE protocols. Significant strong correlations (Pearson r > 0.7, p < 0.05) were found between a set of imaging parameters in SE images and histological biomarkers: E and CI in tumor periphery were associated with microvessel density (MVD) and necrosis, E and CI in the complete tumor with MVD, and rBV in the tumor periphery with MVD. In conclusion, quantitative imaging parameters obtained in SE micro-CT images could be used to characterize angiogenesis and necrosis in the subcutaneous C6 glioma model.

scholarly journals LOTUS-inVivo Micro Computed Tomography System for Imaging of Small Animals and Ex-Vivo Biological Samples

2020 ◽  
Author(s):  
Mohammadreza Fouladi ◽  
Kamran Gholami ◽  
Hossein Ghadiri
Keyword(s):  
Computed Tomography ◽  
Biological Samples ◽  
Ex Vivo ◽  
Small Animal ◽  
Small Animals ◽  
Micro Ct ◽  
Ct Scanner ◽  
Micro Computed Tomography ◽  
Low Contrast ◽  
X Ray

X-ray Computed Tomography (CT), e.g. clinical CT scanners, basically provides Linear Attenuation Coefficients (LACs) of objects under study by the means of algorithmic reconstruction of acquired views of attenuated X-ray passing through the samples in different angles around the imaged sample. Micro Computed Tomography (micro-CT) basically works the same as clinical CT. It provides volumetric information representing the inner structure of objects with a resolution in the micron range. LOTUS-inVivo is a micro-CT scanner dedicated to imaging of small animals and ex-vivo biological samples. In the present study the spatial resolution and Low Contrast Detectability (LCD) of LOTUS-inVivo scanner were evaluated using standard phantoms. We aimed to prove the capability of LOTUS-inVivo for small animal and ex-vivo biological samples imaging using the measured image quality parameters, i.e. spatial resolution and low contrast detectability. By the means of analysis of bar and LCD phantom images, the limiting resolution of LOTUS-inVivo micro-CT scanner was measured about 2.7 µm and has been shown that it’s capable of resolving sizes greater than 12.5 µm. Also, we concluded that LOTUS-inVivo is capable of discriminating tissues with 3% differences in contrast relative to the background, for 1 mm bar size. Thus, the provided technical characteristics in this study have made LOTUS-inVivo as a suitable tool for small animal imaging.

scholarly journals Effect of Collagen-Enhanced Fibrin Sealant on Seroma Formation in a Rat Mastectomy Model

2020 ◽  
Vol 16 (3) ◽  
pp. 137-143
Author(s):  
Jong Seong Kim ◽  
Pil Seon Eo ◽  
Joon Seok Lee ◽  
Jeong Woo Lee ◽  
Kang Young Choi ◽  
...  
Keyword(s):  
Fibrin Sealant ◽  
Three Dimensional ◽  
Axillary Lymph ◽  
Acetate Solution ◽  
Micro Ct ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Ct Volumetry ◽  
Group 2 ◽  
Group 1

Background: Seromas are caused by leakage of lymphovascular fluid into postoperative dead space. This is the most common complication after reconstructive breast surgery. The purpose of this study is to demonstrate the utility of seroma-preventing substances by using a collagen-enhanced fibrin sealant on a rat mastectomy model.Methods: Thirty-six Sprague-Dawley rats were divided into three groups. After mastectomy and axillary lymph node dissection, normal saline was applied to the dead spaces in group 1 (control). In group 2, a collagen-enhanced fibrin sealant was applied, and in group 3, triamcinolone acetate solution was applied. Afterwards, the amount of seroma was measured by three-dimensional micro-computed tomography (3D micro-CT) volumetry analysis and manual aspiration after 7 and 14 days, respectively.Results: The volume of seroma were significantly reduced in groups 2 and 3 compared to group 1 in both 3D micro-CT volumetry analysis and manual aspiration on postoperative day 7 (P<0.001). In addition, the results observed in day 14 also showed a decrease in the amount of seroma analyzed by CT in groups 2 and 3 compared to group 1 (P<0.05). In histopathologic examination inflammation was observed more frequently in group 1 and angiogenesis was more active in group 2.Conclusion: The use of a collagen-enhanced fibrin sealant (Collaseal) is as effective as triamcinolone control injected in a rat mastectomy model.

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