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

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.

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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 ◽

10.1177/1947603519876353 ◽

2019 ◽

pp. 194760351987635 ◽

Cited By ~ 1

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.

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

Contrast Media & Molecular Imaging ◽

10.1155/2017/7368384 ◽

2017 ◽

Vol 2017 ◽

pp. 1-10 ◽

Cited By ~ 3

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.

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

Cancers ◽

10.3390/cancers12113417 ◽

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.

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Microstructure of a Paint Primer - a Data-Constrained Modeling Analysis

Materials Science Forum ◽

10.4028/www.scientific.net/msf.654-656.1686 ◽

2010 ◽

Vol 654-656 ◽

pp. 1686-1689 ◽

Cited By ~ 19

Author(s):

Sam Yang ◽

Da Chao Gao ◽

Tim Muster ◽

Andrew Tulloh ◽

Scott Furman ◽

...

Keyword(s):

Corrosion Inhibitor ◽

Data Sets ◽

Micro Ct ◽

Micro Computed Tomography ◽

X Ray ◽

Microstructure Modeling ◽

Modeling Analysis ◽

Multiphase Systems ◽

Filler Particles ◽

Ct Data

Metallic aerospace components are commonly painted with a primer to improve their corrosion resistance. The primer contains a polymer matrix with embedded corrosion inhibitor and filler particles. Its performance is determined by the microscopic distributions of the particles. Various techniques have been used to quantify such distributions, including X-ray micro-computed tomography (CT). However, its success is sometimes limited by factors such as different particles having similar X-ray CT absorption properties and their size being smaller than the resolution of micro-CT. In this paper, we have performed two X-ray CT measurements on a paint primer sample consisting of SrCrO4 corrosion inhibitor particles and UV-absorbing TiO2 filler particles. Fe and Ti targets were used as X-ray sources with different spectral distributions. The measured CT data sets were used as constraints for a data-constrained microstructure modeling (DCM) prediction of the sample’s microscopic structures. DCM model predictions were compared with experimental elemental surface maps and showed reasonable degree of agreement, suggesting X-ray micro-CT combined with DCM modeling would be a powerful technique for detailing the dynamics of chromate-inhibited primers and other multiphase systems where the components are sensitive to incident X-ray energy.

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

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00281.2012 ◽

2013 ◽

Vol 304 (12) ◽

pp. L831-L843 ◽

Cited By ~ 18

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.

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Preparation and Quantification of Radioactive Particles for Tracking Hydrodynamic Behaviour in Multiphase Reactors

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.625.509 ◽

2014 ◽

Vol 625 ◽

pp. 509-516 ◽

Cited By ~ 3

Author(s):

Mohd Amirul Syafiq Mohd Yunos ◽

Siti Aslina Hussain ◽

Hamdan Mohamed Yusoff ◽

Jaafar Abdullah

Keyword(s):

Micro Ct ◽

Ct Scanner ◽

Micro Computed Tomography ◽

Multiphase Reactors ◽

Simple Method ◽

Qualitative And Quantitative ◽

Hydrodynamic Behaviour ◽

Radioactive Particle ◽

Versatile Technique ◽

Particle Tracer

Radioactive Particle Tracking (RPT) technique has emerged as a potential and versatile technique, both in terms of richness of information and applicability to a variety of multiphase flow systems. RPT is not an off-the-shelf technique and thus has to be developed by the intended user. This paper is intended to present a simple method and procedure for preparing suitable radioactive particles tracer (Au-198 and Sc-46) irradiated simultaneously with neutrons using TRIGA Mark II research reactor. These present work focuses on the performance evaluation of encapsulated gold and scandium particle to be used as single radioactive particle tracer using qualitative and quantitative neutron activation analysis (NAA) and X-ray micro computed tomography (micro-CT) scanner installed at Malaysian Nuclear Agency.

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New Technique for Detecting Cracked Teeth and Evaluating the Crack Depth by Contrast-enhanced Cone Beam Computed Tomography: an in Vitro Study

10.21203/rs.3.rs-1110699/v1 ◽

2021 ◽

Author(s):

Jie Zhou ◽

Jieni Fu ◽

Mo Xiao ◽

Yangyang Lv ◽

Fei Wu ◽

...

Keyword(s):

Computed Tomography ◽

Cone Beam Computed Tomography ◽

Crack Depth ◽

In Vitro Study ◽

New Technique ◽

Cone Beam ◽

Micro Ct ◽

Micro Computed Tomography ◽

Contrast Enhanced

Abstract Background: Develop a new technique based on contrast-enhanced cone beam computed tomography (CBCT) to improve the detection of cracked teeth and the accuracy of crack depth evaluation in vitro. Methods: We developed an in vitro artificial simulation model of cracked teeth. Pre-experimental CBCT (pre-CBCT), and micro-computed tomography (micro-CT) were first performed for all cracked teeth (n = 31). Contrast-enhanced CBCT was then performed by infiltrating the crack with ioversol under vacuum conditions. The results of pre-CBCT, micro-CT, and contrast-enhanced CBCT were recorded. SPSS v.26.0 software (IBM Corp, Somers, NY) and R software , version 3.6.0 (R Foundation for Statistical Computing; http://www.r-project.org/) and RStudio 1.1.463 (RStudio, PBC, Boston, MA, US) were used to perform the statistical analysis for the study.Results: The sensitivities of pre-CBCT and contrast-enhanced CBCT were 48.4%, and 67.7%, respectively. ICC value of crack depth as measured by pre-CBCT and contrast-enhanced CBCT was 0.847 (95% confidence interval:0.380-0.960; P < 0.001). The areas under ROC curves (AUC) of pre-CBCT and contrast-enhanced CBCT were different, the AUC of pre-CBCT was 0.958 (P = 0.000, 95% CI :0.843-1.074), and the AUC of enhanced CBCT was 0.979 (P = 0.000, 95% CI :0.921-1.037), and the difference was not statistically significant (Z=-0.707, P = 0.480). The ICC value of crack depth as measured by contrast-enhanced CBCT and micro-CT was 0.753 (95% CI: 0.248-0.911; P < 0.001). Conclusion: Contrast-enhanced CBCT under vacuum conditions with a contrast medium can only significantly improve the cracks detection rate of cracked teeth, but not measure the crack depths accurately.

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Observation of the Pulp Chamber of Maxillary First Premolars: A Micro-computed Tomographic Study

Current Medical Imaging Formerly Current Medical Imaging Reviews ◽

10.2174/1573405615666191016125937 ◽

2020 ◽

Vol 16 (3) ◽

pp. 224-230

Author(s):

Gozde Serindere ◽

Ceren Aktuna Belgin ◽

Kaan Orhan

Keyword(s):

Root Canal ◽

Age Groups ◽

Slice Thickness ◽

Micro Ct ◽

Micro Computed Tomography ◽

Pulp Chamber ◽

Anatomical Structures ◽

Computed Tomographic ◽

The Mean ◽

Chamber Floor

Background: There are a few studies about the evaluation of maxillary first premolars internal structure with micro-computed tomography (micro-CT). The aim of this study was to assess morphological features of the pulp chamber in maxillary first premolar teeth using micro- CT. Methods: Extracted 15 maxillary first premolar teeth were selected from the patients who were in different age groups. The distance between the pulp orifices, the diameter of the pulp and the width of the pulp chamber floor were measured on the micro-CT images with the slice thickness of 13.6 µm. The number of root canal orifices and the presence of isthmus were evaluated. Results: The mean diameter of orifices was 0.73 mm on the buccal side while it was 0.61 mm on palatinal side. The mean distance between pulp orifices was 2.84 mm. The mean angle between pulp orifices was -21.53°. The mean height of pulp orifices on the buccal side was 4.32 mm while the mean height of pulp orifices on the palatinal side was 3.56 mm. The most observed shape of root canal orifices was flattened ribbon. No isthmus was found in specimens. Conclusion: Minor anatomical structures can be evaluated in more detail with micro-CT. The observation of the pulp cavity was analyzed using micro-CT.

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Micro-Computed Tomography Analysis of Subchondral Bone Regeneration Using Osteochondral Scaffolds in an Ovine Condyle Model

Applied Sciences ◽

10.3390/app11030891 ◽

2021 ◽

Vol 11 (3) ◽

pp. 891

Author(s):

Taylor Flaherty ◽

Maryam Tamaddon ◽

Chaozong Liu

Keyword(s):

Computed Tomography ◽

Bone Regeneration ◽

Subchondral Bone ◽

Volume Ratio ◽

Bone Volume ◽

Osteochondral Defects ◽

Micro Ct ◽

Micro Computed Tomography ◽

Trabecular Thickness ◽

Osteochondral Scaffold

Osteochondral scaffold technology has emerged as a promising therapy for repairing osteochondral defects. Recent research suggests that seeding osteochondral scaffolds with bone marrow concentrate (BMC) may enhance tissue regeneration. To examine this hypothesis, this study examined subchondral bone regeneration in scaffolds with and without BMC. Ovine stifle condyle models were used for the in vivo study. Two scaffold systems (8 mm diameter and 10 mm thick) with and without BMC were implanted into the femoral condyle, and the tissues were retrieved after six months. The retrieved femoral condyles (with scaffold in) were examined using micro-computed tomography scans (micro-CT), and the micro-CT data were further analysed by ImageJ with respect to trabecular thickness, bone volume to total volume ratio (BV/TV) ratio, and degree of anisotropy of bone. Statistical analysis compared bone regeneration between scaffold groups and sub-set regions. These results were mostly insignificant (p < 0.05), with the exception of bone volume to total volume ratio when comparing scaffold composition and sub-set region. Additional trends in the data were observed. These results suggest that the scaffold composition and addition of BMC did not significantly affect bone regeneration in osteochondral defects after six months. However, this research provides data which may guide the development of future treatments.

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Modelling the skeletal muscle injury recovery using in vivo contrast-enhanced micro-CT: a proof-of-concept study in a rat model

European Radiology Experimental ◽

10.1186/s41747-020-00163-4 ◽

2020 ◽

Vol 4 (1) ◽

Cited By ~ 1

Author(s):

Bruno Paun ◽

Daniel García Leon ◽

Alex Claveria Cabello ◽

Roso Mares Pages ◽

Elena de la Calle Vargas ◽

...

Keyword(s):

Skeletal Muscle ◽

Rat Model ◽

Muscle Injury ◽

Micro Ct ◽

Skeletal Muscle Injury ◽

Monitoring Time ◽

Contrast Enhanced Ct ◽

Contrast Enhanced ◽

Injury Recovery

Abstract Background Skeletal muscle injury characterisation during healing supports trauma prognosis. Given the potential interest of computed tomography (CT) in muscle diseases and lack of in vivo CT methodology to image skeletal muscle wound healing, we tracked skeletal muscle injury recovery using in vivo micro-CT in a rat model to obtain a predictive model. Methods Skeletal muscle injury was performed in 23 rats. Twenty animals were sorted into five groups to image lesion recovery at 2, 4, 7, 10, or 14 days after injury using contrast-enhanced micro-CT. Injury volumes were quantified using a semiautomatic image processing, and these values were used to build a prediction model. The remaining 3 rats were imaged at all monitoring time points as validation. Predictions were compared with Bland-Altman analysis. Results Optimal contrast agent dose was found to be 20 mL/kg injected at 400 μL/min. Injury volumes showed a decreasing tendency from day 0 (32.3 ± 12.0mm3, mean ± standard deviation) to day 2, 4, 7, 10, and 14 after injury (19.6 ± 12.6, 11.0 ± 6.7, 8.2 ± 7.7, 5.7 ± 3.9, and 4.5 ± 4.8 mm3, respectively). Groups with single monitoring time point did not yield significant differences with the validation group lesions. Further exponential model training with single follow-up data (R2 = 0.968) to predict injury recovery in the validation cohort gave a predictions root mean squared error of 6.8 ± 5.4 mm3. Further prediction analysis yielded a bias of 2.327. Conclusion Contrast-enhanced CT allowed in vivo tracking of skeletal muscle injury recovery in rat.

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