scholarly journals Non-invasive imaging demonstrates clinical features of ankylosing spondylitis in a rat adjuvant model: a case study

2016 ◽  
Author(s):  
N. Accart ◽  
J. Dawson ◽  
F. Kolbinger ◽  
I. Kramer ◽  
N. Beckmann
Keyword(s):  
Ankylosing Spondylitis ◽  
Bone Remodeling ◽  
Drug Testing ◽  
Soft Tissues ◽  
Experimental Period ◽  
Micro Ct ◽  
Non Invasive ◽  
Spine Imaging ◽  
Bone Damage

Ankylosing spondylitis is a common rheumatic disease involving both inflammatory erosive osteopenia and bony overgrowth. Main disease features are recapitulated in small rodents challenged with complete Freund’s adjuvant. MRI was used to follow longitudinally in vivo changes induced in the rat spine and micro-CT as terminal assessment of bone damage. Histochemistry methods were used to validate these imaging modalities in view of preclinical drug testing and translational applications of spine imaging. Animals were examined using a 3D fat-suppressed gradient-echo sequence, following the injection of gadolinium. At the end of the study, spines were excised for micro-CT and histological examination. Signals reflecting inflammation were detected at levels L5-L6 of the lumbar spine throughout the experimental period, peaking at day 27 after adjuvant. At day 14 the inflammatory response occurred along ligaments but it expanded to nearby soft tissues at later time points. From day 27 onwards inflammation was also detected within the bone, in areas where erosion occurred, and bone-like structures were formed. Micro-CT showed bone remodeling. Histology of isolated spines confirmed the inflammation and bone remodeling observed in vivo. The present study including three complementary approaches clearly demonstrates the potential of imaging for longitudinal assessments of changes in the spine in this animal model in view of preclinical pharmacological studies. The excellent correlation seen between the in vivo images and the histology underlines its fundamental role in the validation of non-invasive imaging readouts.

Non-Invasive Measurement of In-Vivo Elasticity of Skeletal Muscles with MR-Elastography

2007 ◽  
Vol 342-343 ◽  
pp. 901-904
Author(s):  
Yu Bong Kang ◽  
T. Oida ◽  
Duk Young Jung ◽  
A. Fukuma ◽  
T. Azuma ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Modulus ◽  
Skeletal Muscles ◽  
Soft Tissues ◽  
Viscosity Coefficient ◽  
Non Invasive ◽  
Novel Method ◽  
Human Calf ◽  
Invasive Measurement

In order to evaluate the mechanical properties of the human skeletal muscles, the elasticity and viscosity of the human calf muscles were measured with Magnetic Resonance Elastography (MRE). MRE is a novel method to measure the mechanical properties of living soft tissues in vivo quantitatively by observing the strain waves propagated in the object. In this study, the shear modulus and viscosity coefficient were measured with MRE. The shear modulus was 3.7 kPa in relaxed state, and increased with increasing the muscle forces. Interestingly, the viscosity was changed with the vibration frequency applied to the muscles, that was 4.5 Pa·s at 100Hz vibration and 2.4 Pa·s at 200Hz vibration. This shows clearly the visco-elastic property.

scholarly journals PEG-modified gadolinium nanoparticles as contrast agents for in vivo micro-CT

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charmainne Cruje ◽  
P. Joy Dunmore-Buyze ◽  
Eric Grolman ◽  
David W. Holdsworth ◽  
Elizabeth R. Gillies ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Blood Pool ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Poly Ethylene

AbstractVascular research is largely performed in rodents with the goal of developing treatments for human disease. Micro-computed tomography (micro-CT) provides non-destructive three-dimensional imaging that can be used to study the vasculature of rodents. However, to distinguish vasculature from other soft tissues, long-circulating contrast agents are required. In this study, we demonstrated that poly(ethylene glycol) (PEG)-coated gadolinium nanoparticles can be used as a vascular contrast agent in micro-CT. The coated particles could be lyophilized and then redispersed in an aqueous solution to achieve 100 mg/mL of gadolinium. After an intravenous injection of the contrast agent into mice, micro-CT scans showed blood pool contrast enhancements of at least 200 HU for 30 min. Imaging and quantitative analysis of gadolinium in tissues showed the presence of contrast agent in clearance organs including the liver and spleen and very low amounts in other organs. In vitro cell culture experiments, subcutaneous injections, and analysis of mouse body weight suggested that the agents exhibited low toxicity. Histological analysis of tissues 5 days after injection of the contrast agent showed cytotoxicity in the spleen, but no abnormalities were observed in the liver, lungs, kidneys, and bladder.

scholarly journals Why Are Viscosity and Nonlinearity Bound to Make an Impact in Clinical Elastographic Diagnosis?

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2379 ◽  
Author(s):  
Guillermo Rus ◽  
Inas H. Faris ◽  
Jorge Torres ◽  
Antonio Callejas ◽  
Juan Melchor
Keyword(s):  
Soft Tissues ◽  
Elastic Parameters ◽  
Tissue Microstructure ◽  
Non Invasive ◽  
Recent Developments ◽  
Mechanical Biomarkers ◽  
Nonlinear Elastic

The adoption of multiscale approaches by the biomechanical community has caused a major improvement in quality in the mechanical characterization of soft tissues. The recent developments in elastography techniques are enabling in vivo and non-invasive quantification of tissues’ mechanical properties. Elastic changes in a tissue are associated with a broad spectrum of pathologies, which stems from the tissue microstructure, histology and biochemistry. This knowledge is combined with research evidence to provide a powerful diagnostic range of highly prevalent pathologies, from birth and labor disorders (prematurity, induction failures, etc.), to solid tumors (e.g., prostate, cervix, breast, melanoma) and liver fibrosis, just to name a few. This review aims to elucidate the potential of viscous and nonlinear elastic parameters as conceivable diagnostic mechanical biomarkers. First, by providing an insight into the classic role of soft tissue microstructure in linear elasticity; secondly, by understanding how viscosity and nonlinearity could enhance the current diagnosis in elastography; and finally, by compounding preliminary investigations of those elastography parameters within different technologies. In conclusion, evidence of the diagnostic capability of elastic parameters beyond linear stiffness is gaining momentum as a result of the technological and imaging developments in the field of biomechanics.

scholarly journals Visualization capabilities of experimental oncological models in small laboratory animals

2018 ◽  
Vol 9 (4) ◽  
pp. 105-112 ◽  
Author(s):  
Valeria A. Pechatnikova ◽  
Alexander P. Trashkov ◽  
Maria A. Zelenenko ◽  
Nikolay A. Verlov ◽  
Grigorii A. Chizh ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Pathological Process ◽  
Nerve Fibers ◽  
Laboratory Animals ◽  
Small Laboratory ◽  
Internal Organs ◽  
Imaging Methods ◽  
Non Invasive ◽  
Long Time

For a long time non-invasive imaging methods have been inaccessible in preclinical practice; their introduction lately has broadened the boundaries of relevant studies and felicitated new approaches to solving fundamental problems. Up-to-date imaging methods constitute an essential component of preclinical and translational biomedical research allowing quick and non-invasive extended representation of structural organization and functional characteristics of pathological processes in vivo. Methods of radiation diagnosis and nuclear magnetic resonance allow to assess the state of bones, soft tissues, internal organs, blood vessels and peripheral nerve fibers in various animals, not only mammals, but also fish, amphibians, reptiles and insects. Multiparametric studies can uniquely localize any anatomical structure or pathological process. However, not all existing techniques are applicable to various oncological models of small laboratory animals.

Urine Cells-derived iPSCs: An Upcoming Frontier in Regenerative Medicine

2021 ◽  
Vol 28 ◽  
Author(s):  
Sanjeev Gautam ◽  
Sangita Biswas ◽  
Birbal Singh ◽  
Ying Guo ◽  
Peng Deng ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Drug Testing ◽  
Diagnostic Tools ◽  
Cell Therapies ◽  
Non Invasive ◽  
Key Issues ◽  
Induced Pluripotent

: There is a momentous surge in the development of stem cell technology as a therapeutic and diagnostic tools. Stem cell-derived cells are currently used in various clinical trials. However, key issues and challenges involve the low differentiation efficiency, integration, and functioning of transplanted stem cells-derived cells. Extraction of bone marrow, adipose, or other mesenchymal stem cells (MSCs) involves invasive methods, specialized skills, and expensive technologies. Urine-derived cells, on the other hand, are obtained by non-invasive methods. Samples can be obtained repeatedly from patients of any age. Urine-derived cells are used to generate reprogrammed or induced pluripotent stem cells (iPSCs), which can be cultured, and differentiated into various types of cell lineages for biomedical investigations and drug testing in vitro or in vivo using model animals of human diseases. Urine cell-derived iPSCs (UiPSCs) have emerged as a major area of research and immense therapeutic significance. Given that preliminary preclinical studies are successful in terms of safety and as a regenerative tool, the UiPSCs will pave the way to develop and expedite various types of autologous stem cell therapies.

scholarly journals Non-invasive detection of protein metabolism in vivo by n.m.r. spectroscopy. Application of a novel 19F-containing residualizing label

1989 ◽  
Vol 264 (3) ◽  
pp. 829-835 ◽  
Author(s):  
A Daugherty ◽  
N N Becker ◽  
L A Scherrer ◽  
B E Sobel ◽  
J J H Ackerman ◽  
...  
Keyword(s):  
Intravenous Administration ◽  
Half Life ◽  
Soft Tissues ◽  
Degradation Products ◽  
Chemical Shifts ◽  
Whole Body ◽  
Hepatic Tissue ◽  
Protein Accumulation ◽  
Non Invasive

Protein residualizing labels facilitate localization of tissue sites of protein catabolism and the quantification of protein accumulation because of their prolonged intracellular retention of protein accumulation because of their prolonged intracellular retention times. Radioiodinated residualizing labels have been used to define the metabolism of a wide variety of proteins, but this has necessitated destructive analysis. Here we describe the implementation and validation of a novel 19F-containing residualizing label for protein, NN-dilactitol-3,5-bis(trifluoromethyl)benzylamine (DLBA), that permits the non-invasive assessment of protein accumulation and catabolism by n.m.r. spectroscopy in vivo. DLBA comprises a reporter molecule containing six equivalent 19F atoms. 19F is strongly n.m.r.-active, has 100% natural abundance, and is present in minimal background concentrations in soft tissues. We validated the use of DLBA as a protein-labelling compound by coupling to asialofetuin (ASF), a protein that is recognized exclusively by hepatic tissue via a saturable receptor-mediated process. Coupling of DLBA to ASF by reductive amination had no effect on the physiological receptor-mediated uptake of the protein in rat liver in vivo. The 19F-n.m.r. spectrum of DLBA exhibited a single peak that was subject to a small chemical-shift change and broadening after coupling to ASF. Pronase digestion of DLBA-ASF was performed to simulate intracellular degradation products, and resulted in a narrower set of resonances, with chemical shifts intermediate between those of uncoupled DLBA and DLBA-ASF. Intravenous administration of DLBA-ASF to rats followed by quantification of 19F in homogenates of liver tissue indicated that the half-life of residence time of degradation products from DLBA-ASF in liver was approx. 2 days. This intracellular half-life was comparable with that described for similar residualizing labels that contain radioiodide as a reporter. Similar results for the half-life of retention were obtained non-destructively and non-invasively in situ with the use of a whole-body radio-frequency antenna to acquire sequential spectra over 80 h after intravenous administration of DLBA-ASF. Quantification of these spectra demonstrated an initial accumulation of DLBA-ASF in liver followed by an expected gradual loss of 19F-labelled degradation products. The approach developed offers promise for the sequential and longitudinal characterization of metabolism of specific proteins in individual experimental animals and ultimately in human subjects.

Sonic Diagnosis of Skeletal Defects: A Preliminary Study

1987 ◽  
Vol 1 (1) ◽  
pp. 39-44 ◽  
Author(s):  
S. Kwon ◽  
J.L. Katz
Keyword(s):  
Soft Tissues ◽  
Human Subjects ◽  
Connective Tissues ◽  
Non Invasive ◽  
Diagnostic Use ◽  
Tissue Phantom ◽  
Skeletal Defects ◽  
Preliminary Study ◽  
A New Technique

Non-invasive in vivo assessment of the mechanical properties of hard connective tissues and its clinical applications has been hampered in part because of coupling effects with the surrounding soft tissues. Here, we present a new technique that can, through correlation analysis, potentially separate the effects of the soft tissues and provide information about the underlying hard connective tissues. Preliminary studies on an animal model and on human subjects, as well as on an ultrasonically equivalent tissue phantom, show that this technique minimizes the effects of the soft tissues and is quite sensitive to defects in the hard connective tissues. It is suggested that suitable adaptations of this technique may prove of diagnostic use in clinical dentistry as well.

scholarly journals Mechanics of ultrasound elastography

2017 ◽  
Vol 473 (2199) ◽  
pp. 20160841 ◽  
Author(s):  
Guo-Yang Li ◽  
Yanping Cao
Keyword(s):  
Soft Tissues ◽  
Soft Materials ◽  
Ultrasound Elastography ◽  
Practical Applications ◽  
Linear Elastic ◽  
Non Invasive ◽  
Anisotropic Elastic ◽  
Non Destructive

Ultrasound elastography enables in vivo measurement of the mechanical properties of living soft tissues in a non-destructive and non-invasive manner and has attracted considerable interest for clinical use in recent years. Continuum mechanics plays an essential role in understanding and improving ultrasound-based elastography methods and is the main focus of this review. In particular, the mechanics theories involved in both static and dynamic elastography methods are surveyed. They may help understand the challenges in and opportunities for the practical applications of various ultrasound elastography methods to characterize the linear elastic, viscoelastic, anisotropic elastic and hyperelastic properties of both bulk and thin-walled soft materials, especially the in vivo characterization of biological soft tissues.

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