scholarly journals Ex vivo characterization of articular cartilage and bone lesions in a rabbit ACL transection model of osteoarthritis using MRI and micro-CT

2004 ◽  
Vol 12 (12) ◽  
pp. 986-996 ◽  
Author(s):  
Danika L. Batiste ◽  
Alexandra Kirkley ◽  
Sheila Laverty ◽  
Lisa M.F. Thain ◽  
Alison R. Spouge ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Ex Vivo ◽  
Bone Lesions ◽  
Micro Ct ◽  
Acl Transection

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 A new pipeline to automatically segment and semi-automatically measure bone length on 3D models obtained by Computed Tomography

2020 ◽  
Author(s):  
Santiago Beltran Diaz ◽  
Xinli Qu ◽  
Sarah Fung ◽  
Michael de Veer ◽  
Olga Panagiotopoulou ◽  
...  
Keyword(s):  
Ex Vivo ◽  
3D Models ◽  
Linear Measurement ◽  
Long Bone ◽  
Micro Ct ◽  
Bone Length ◽  
Automated Algorithm ◽  
Highly Correlated ◽  
User Friendly

AbstractThe characterization of developmental phenotypes often relies on the accurate linear measurement of structures that are small and require laborious preparation. This is tedious and prone to errors, especially when repeated for the multiple replicates that are required for statistical analysis, or when multiple distinct structures have to be analysed. To address this issue, we have developed a pipeline for characterization of long-bone length using micro-CT scans. It involves a semi-automated algorithm that uses the Mimics Innovation Suite package (Materialise) for automatic thresholding and fast interactive isolation and 3D-model generation of the main limb bones. All the image-processing steps are included in a user-friendly Python script. We show that the appropriate combination of scanning and in silico analysis conditions yields fast and reproducible length results, highly correlated with the measurements obtained via ex vivo skeletal preparations. Moreover, since micro-CT is not destructive, the samples can be used afterwards for histology or other applications. Our new pipeline will help developmental biologists and evolution researchers to achieve fast, reproducible and non-destructive length measurement of bone samples from multiple animal species.Summary statementBeltran Diaz et al. present a semi-automated pipeline for fast and versatile characterization of bone length from micro-CT images of mouse developmental samples.

scholarly journals Synchrotron- and laboratory-based X-ray phase-contrast imaging for imaging mouse articular cartilage in the absence of radiopaque contrast agents

2014 ◽  
Vol 372 (2010) ◽  
pp. 20130127 ◽  
Author(s):  
Massimo Marenzana ◽  
Charlotte K. Hagen ◽  
Patricia Das Neves Borges ◽  
Marco Endrizzi ◽  
Magdalena B. Szafraniec ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Soft Tissue ◽  
Phase Contrast ◽  
Ex Vivo ◽  
Phase Changes ◽  
Phase Contrast Imaging ◽  
Laboratory System ◽  
Micro Ct ◽  
Contrast Imaging ◽  
X Ray

The mouse model of osteoarthritis (OA) has been recognized as the most promising research tool for the identification of new OA therapeutic targets. However, this model is currently limited by poor throughput, dependent on the extremely time-consuming histopathology assessment of the articular cartilage (AC). We have recently shown that AC in the rat tibia can be imaged both in air and in saline solution using a laboratory system based on coded-aperture X-ray phase-contrast imaging (CAXPCi). Here, we explore ways to extend the methodology for imaging the much thinner AC of the mouse, by means of gold-standard synchrotron-based phase-contrast methods. Specifically, we have used analyser-based phase-contrast micro-computed tomography (micro-CT) for its high sensitivity to faint phase changes, coupled with a high-resolution (4.5 μm pixel) detector. Healthy, diseased (four weeks post induction of OA) and artificially damaged mouse AC was imaged at the Elettra synchrotron in Trieste, Italy, using the above method. For validation, we used conventional micro-CT combined with radiopaque soft-tissue staining and standard histomorphometry. We show that mouse cartilage can be visualized correctly by means of the synchrotron method. This suggests that: (i) further developments of the laboratory-based CAXPCi system, especially in terms of pushing the resolution limits, might have the potential to resolve mouse AC ex vivo and (ii) additional improvements may lead to a new generation of CAXPCi micro-CT scanners which could be used for in vivo longitudinal pre-clinical imaging of soft tissue at resolutions impossible to achieve by current MRI technology.

Efficacy of single-source rapid kV-switching dual-energy CT for characterization of non-uric acid renal stones: a prospective ex vivo study using anthropomorphic phantom

2019 ◽  
Vol 45 (4) ◽  
pp. 1092-1099
Author(s):  
Roberto Cannella ◽  
Mohammed Shahait ◽  
Alessandro Furlan ◽  
Feng Zhang ◽  
Joel D. Bigley ◽  
...  
Keyword(s):  
Uric Acid ◽  
Ex Vivo ◽  
Renal Stones ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Single Source ◽  
Anthropomorphic Phantom ◽  
Ex Vivo Study

scholarly journals Morpho-molecular ex vivo detection and grading of non-muscle-invasive bladder cancer using forward imaging probe based multimodal optical coherence tomography and Raman spectroscopy

The Analyst ◽  
2020 ◽  
Vol 145 (4) ◽  
pp. 1445-1456 ◽  
Author(s):  
Fabian Placzek ◽  
Eliana Cordero Bautista ◽  
Simon Kretschmer ◽  
Lara M. Wurster ◽  
Florian Knorr ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Optical Coherence Tomography ◽  
Imaging System ◽  
Ex Vivo ◽  
Large Field ◽  
Optical Coherence ◽  
Fiber Optic Probe ◽  
Optic Probe ◽  
Muscle Invasive

Characterization of bladder biopsies, using a combined fiber optic probe-based optical coherence tomography and Raman spectroscopy imaging system that allows a large field-of-view imaging and detection and grading of cancerous bladder lesions.

scholarly journals Consequences of SUR2[A478V] Mutation in Skeletal Muscle of Murine Model of Cantu Syndrome

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1791
Author(s):  
Rosa Scala ◽  
Fatima Maqoud ◽  
Nicola Zizzo ◽  
Giuseppe Passantino ◽  
Antonietta Mele ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Katp Channel ◽  
Ex Vivo ◽  
Channel Modulation ◽  
Flexor Digitorum Brevis ◽  
Inflammatory Edema ◽  
Flexor Digitorum ◽  
Channel Currents

(1) Background: Cantu syndrome (CS) arises from gain-of-function (GOF) mutations in the ABCC9 and KCNJ8 genes, which encode ATP-sensitive K+ (KATP) channel subunits SUR2 and Kir6.1, respectively. Most CS patients have mutations in SUR2, the major component of skeletal muscle KATP, but the consequences of SUR2 GOF in skeletal muscle are unknown. (2) Methods: We performed in vivo and ex vivo characterization of skeletal muscle in heterozygous SUR2[A478V] (SUR2wt/AV) and homozygous SUR2[A478V] (SUR2AV/AV) CS mice. (3) Results: In SUR2wt/AV and SUR2AV/AV mice, forelimb strength and diaphragm amplitude movement were reduced; muscle echodensity was enhanced. KATP channel currents recorded in Flexor digitorum brevis fibers showed reduced MgATP-sensitivity in SUR2wt/AV, dramatically so in SUR2AV/AV mice; IC50 for MgATP inhibition of KATP currents were 1.9 ± 0.5 × 10−5 M in SUR2wt/AV and 8.6 ± 0.4 × 10−6 M in WT mice and was not measurable in SUR2AV/AV. A slight rightward shift of sensitivity to inhibition by glibenclamide was detected in SUR2AV/AV mice. Histopathological and qPCR analysis revealed atrophy of soleus and tibialis anterior muscles and up-regulation of atrogin-1 and MuRF1 mRNA in CS mice. (4) Conclusions: SUR2[A478V] “knock-in” mutation in mice impairs KATP channel modulation by MgATP, markedly so in SUR2AV/AV, with atrophy and non-inflammatory edema in different skeletal muscle phenotypes.

scholarly journals Optical Biomarkers for the Diagnosis of Osteoarthritis through Raman Spectroscopy: Radiological and Biochemical Validation Using Ex Vivo Human Cartilage Samples

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 546
Author(s):  
Paula Casal-Beiroa ◽  
Vanesa Balboa-Barreiro ◽  
Natividad Oreiro ◽  
Sonia Pértega-Díaz ◽  
Francisco J. Blanco ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Articular Cartilage ◽  
Ex Vivo ◽  
Cartilage Degradation ◽  
Calcium Pyrophosphate ◽  
Calcium Pyrophosphate Dihydrate ◽  
Label Free ◽  
Molecular Fingerprint ◽  
Human Cartilage ◽  
Biochemical Validation

Osteoarthritis (OA) is the most common rheumatic disease, characterized by progressive articular cartilage degradation. Raman spectroscopy (RS) has been recently proposed as a label-free tool to detect molecular changes in musculoskeletal tissues. We used cartilage samples derived from human femoral heads to perform an ex vivo study of different Raman signals and ratios, related to major and minor molecular components of articular cartilage, hereby proposed as candidate optical biomarkers for OA. Validation was performed against the radiological Kellgren–Lawrence (K-L) grading system, as a gold standard, and cross-validated against sulfated glycosaminoglycans (sGAGs) and total collagens (Hyp) biochemical contents. Our results showed a significant decrease in sGAGs (SGAGs, A1063 cm−1/A1004 cm−1) and proteoglycans (PGs, A1375 cm−1/A1004 cm−1) and a significant increase in collagen disorganization (ColD/F, A1245 cm−1/A1270 cm−1), with OA severity. These were correlated with sGAGs or Hyp contents, respectively. Moreover, the SGAGs/HA ratio (A1063 cm−1/A960 cm−1), representing a functional matrix, rich in proteoglycans, to a mineralized matrix-hydroxyapatite (HA), was significantly lower in OA cartilage (K-L I vs. III–IV, p < 0.05), whilst the mineralized to collagenous matrix ratio (HA/Col, A960 cm−1/A920 cm−1) increased, being correlated with K-L. OA samples showed signs of tissue mineralization, supported by the presence of calcium crystals-related signals, such as phosphate, carbonate, and calcium pyrophosphate dihydrate (MGP, A960 cm−1/A1004 cm−1, MGC, A1070 cm−1/A1004 cm−1 and A1050 cm−1/A1004 cm−1). Finally, we observed an increase in lipids ratio (IL, A1450 cm−1/A1670 cm−1) with OA severity. As a conclusion, we have described the molecular fingerprint of hip cartilage, validating a panel of optical biomarkers and the potential of RS as a complementary diagnostic tool for OA.

scholarly journals Design of a force-measuring setup for colorectal compression anastomosis and first ex-vivo results

2021 ◽  
Author(s):  
Jana Steger ◽  
Isabella Patzke ◽  
Maximilian Berlet ◽  
Stefanie Ficht ◽  
Markus Eblenkamp ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Tissue Fixation ◽  
Force Transmission ◽  
Tissue Thickness ◽  
Colon Tissue ◽  
Device Development ◽  
Compression Anastomosis ◽  
Technical Requirements ◽  
Significant Difference

Abstract Purpose The introduction of novel endoscopic instruments is essential to reduce trauma in visceral surgery. However, endoscopic device development is hampered by challenges in respecting the dimensional restrictions, due to the narrow access route, and by achieving adequate force transmission. As the overall goal of our research is the development of a patient adaptable, endoscopic anastomosis manipulator, biomechanical and size-related characterization of gastrointestinal organs are needed to determine technical requirements and thresholds to define functional design and load-compatible dimensioning of devices. Methods We built an experimental setup to measure colon tissue compression piercing forces. We tested 54 parameter sets, including variations of three tissue fixation configurations, three piercing body configurations (four, eight, twelve spikes) and insertion trajectories of constant velocities (5 mms−1, 10 mms−1,15 mms−1) and constant accelerations (5 mms−2, 10 mms−2, 15 mms−2) each in 5 samples. Furthermore, anatomical parameters (lumen diameter, tissue thickness) were recorded. Results There was no statistically significant difference in insertion forces neither between the trajectory groups, nor for variation of tissue fixation configurations. However, we observed a statistically significant increase in insertion forces for increasing number of spikes. The maximum mean peak forces for four, eight and twelve spikes were 6.4 ± 1.5 N, 13.6 ± 1.4 N and 21.7 ± 5.8 N, respectively. The 5th percentile of specimen lumen diameters and pierced tissue thickness were 24.1 mm and 2.8 mm, and the 95th percentiles 40.1 mm and 4.8 mm, respectively. Conclusion The setup enabled reliable biomechanical characterization of colon material, on the base of which design specifications for an endoscopic anastomosis device were derived. The axial implant closure unit must enable axial force transmission of at least 28 N (22 ± 6 N). Implant and applicator diameters must cover a range between 24 and 40 mm, and the implant gap, compressing anastomosed tissue, between 2 and 5 mm.

Sign in / Sign up

Export Citation Format

Share Document