Objective: To investigate the potential of quantitative susceptibility mapping (QSM) and T2* relaxation time mapping to determine mechanical and structural properties of articular cartilage via univariate and multivariate analysis.
Methods: Samples were obtained from a cartilage repair study, in which surgically induced full-thickness chondral defects in the stifle joints of seven Shetland ponies caused post-traumatic osteoarthritis (14 samples). Control samples were collected from non-operated joints of three animals (6 samples). Magnetic resonance imaging (MRI) was performed at 9.4 T, using a 3-D multi-echo gradient echo sequence. Biomechanical testing, digital densitometry (DD) and polarized light microscopy (PLM) were utilized as reference methods. To compare MRI parameters with reference parameters (equilibrium and dynamic moduli, proteoglycan content, collagen fiber angle and -anisotropy), depth-wise profiles of MRI parameters were acquired at the biomechanical testing locations. Partial least squares regression (PLSR) and Spearman's rank correlation were utilized in data analysis.
Results: PLSR indicated a moderate-to-strong correlation (ρ = 0.49-0.66) and a moderate correlation (ρ = 0.41-0.55) between the reference values and T2* relaxation time and QSM profiles, respectively (excluding superficial-only results). PLSR correlations were noticeably higher than direct correlations between bulk MRI and reference parameters. 3-D parametric surface maps revealed spatial variations in the MRI parameters between experimental and control groups.
Conclusion: Quantitative parameters from 3-D multi-echo gradient echo MRI can be utilized to predict the properties of articular cartilage. With PLSR, especially the T2* relaxation time profile appeared to correlate with the properties of cartilage. Furthermore, the results suggest that degeneration affects the QSM-contrast in the cartilage. However, this change in contrast is not easy to quantify.
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http://dx.doi.org/10.1016/j.joca.2019.06.009 | DOI Listing |
Ann Biomed Eng
January 2025
School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47907, USA.
Purpose: To evaluate the mechanical wear of cartilage with different types of degradation.
Methods: Bovine osteochondral explants were treated with interleukin-1β (IL-1β) to mimic inflammatory conditions, with chondroitinase ABC (ChABC) to specifically remove glycosaminoglycans (GAGs), or with collagenase to degrade the collagen network during 5 days of culture. Viscoelastic properties of cartilage were characterized via indentation.
Polymers (Basel)
January 2025
Department of Engineering, University of Palermo, Viale delle Scienze, Edificio 6, 90128 Palermo, Italy.
This paper deals with the design of novel epoxy adhesives by incorporating thermoplastic polymers such as polyetherimide (PEI) and poly(ε-caprolactone) (PCL) into a bio-based and recyclable epoxy resin, known as Polar Bear. The adhesives were characterized by their mechanical (quasi-static and dynamic) and rheological properties, thermal stability, and adhesion properties in single-lap joints tested at three different temperatures (i.e.
View Article and Find Full Text PDFPharmaceuticals (Basel)
December 2024
College of Korea Medicine, Woosuk University, Jeonju-si 54986, Republic of Korea.
Monosodium urate crystal accumulation in the joints is the cause of gout, an inflammatory arthritis that is initiated by elevated serum uric acid levels. It is the most prevalent form of inflammatory arthritis, affecting millions worldwide, and requires effective treatments. The necessity for alternatives with fewer side effects is underscored by the frequent adverse effects of conventional therapies, such as urate-lowering drugs.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
School of Materials Science and Engineering, Tianjin University, Tianjin 300354, China.
Ultrasonic welding (USW) is considered one of the most suitable methods to join semi-crystalline carbon fiber-reinforced thermoplastics (CFRTPs). The degree of crystallinity (DoC) of the semi-crystalline resin will affect the ultrasonic welding process by affecting the mechanical properties of the base material. In addition, ultrasonic welding parameters will affect the joint performance by affecting the DoC of the welded material at the welding interface.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
College of Intelligent Manufacturing, Huanghuai University, Zhumadian 463000, China.
Friction-stir-welded dissimilar AA2024/AA7075 joints have an apparent influence on grain and texture development at the weld interface due to differences in physical and chemical properties between the two aluminum alloys. In this work, the effect of tool shoulder profile on grain structure and texture evolution in the center interface zone (CIZ) and bottom interface zone (BIZ) of dissimilar AA2024/AA7075 joints were quantitatively studied by electron back-scattering diffraction (EBSD). The results indicate that abundant fine and coarse equiaxial grains are produced in the CIZ and BIZ of the joints produced with a concentric circle shoulder (CCS) and three-helix shoulder (THS), and the average grain size of the BIZ is lower than that of the CIZ for the same CCS or THS joint.
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