1
|
Fernquest S, Palmer A, Pereira C, Arnold C, Hirons E, Broomfield J, Newman S, Glyn-Jones S. The Response of Hip Joint Cartilage to Exercise in Children: An MRI Study Using T2-Mapping. Cartilage 2021; 13:1761S-1771S. [PMID: 32532161 PMCID: PMC8808918 DOI: 10.1177/1947603520931182] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE The aim of this study was to determine the effects of activity and cam morphology on cartilage composition during adolescence and investigate the development of cartilage composition with age. DESIGN Cross-sectional observational cohort study of individuals from football club academies and an age-matched control population, aged 9 to 18 years. Assessments included questionnaires and T2-mapping of hips. Primary imaging outcome measures were T2 relaxation time of acetabular and femoral cartilage, average alpha angle, and lateral epiphyseal extension. RESULTS The cohort consisted of 109 elite male footballers, 49 male controls, and 51 female controls. Elite male footballers had an acetabular cartilage T2 value 4.85 ms greater than male controls (P < 0.001). A significant positive correlation existed between Physical Activity Questionnaire Score and acetabular cartilage T2 value (coefficient 1.07, P < 0.001) and femoral cartilage T2 value (coefficient 0.66, P = 0.032). Individuals with a closed physis had an acetabular cartilage T2 value 7.86 ms less than individuals with an open physis. Acetabular cartilage T2 values decreased with age in elite footballers. No correlation existed between alpha angle and anterosuperior acetabular cartilage T2 value and no difference in T2 value existed between individuals with and without cam morphology. CONCLUSIONS This study demonstrates that high activity levels may significantly affect acetabular cartilage composition during adolescence, but cam morphology may not detrimentally affect cartilage composition until after adolescence.
Collapse
Affiliation(s)
- Scott Fernquest
- Botnar Research Centre, Nuffield
Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University
of Oxford, Oxford, UK,Scott Fernquest, Botnar Research Centre,
Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences,
University of Oxford, Old Road, Oxford, OX3 7LD, UK.
| | - Antony Palmer
- Botnar Research Centre, Nuffield
Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University
of Oxford, Oxford, UK
| | - Claudio Pereira
- Botnar Research Centre, Nuffield
Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University
of Oxford, Oxford, UK
| | - Calum Arnold
- Botnar Research Centre, Nuffield
Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University
of Oxford, Oxford, UK
| | - Emma Hirons
- Botnar Research Centre, Nuffield
Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University
of Oxford, Oxford, UK
| | - John Broomfield
- Botnar Research Centre, Nuffield
Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University
of Oxford, Oxford, UK
| | - Simon Newman
- Botnar Research Centre, Nuffield
Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University
of Oxford, Oxford, UK
| | - Sion Glyn-Jones
- Botnar Research Centre, Nuffield
Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University
of Oxford, Oxford, UK
| |
Collapse
|
2
|
Hafner T, Post M, Said O, Schad P, Schock J, Abrar DB, Knobe M, Kuhl C, Truhn D, Nebelung S. Identifying the imaging correlates of cartilage functionality based on quantitative MRI mapping - The collagenase exposure model. Acta Biomater 2020; 117:310-321. [PMID: 32980541 DOI: 10.1016/j.actbio.2020.09.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 09/16/2020] [Accepted: 09/17/2020] [Indexed: 01/05/2023]
Abstract
Cartilage functionality is determined by tissue structure and composition. If altered, cartilage is predisposed to premature degeneration. This pathomimetical study of early osteoarthritis evaluated the dose-dependant effects of collagenase-induced collagen disintegration and proteoglycan depletion on cartilage functionality as assessed by serial T1, T1ρ, T2, and T2* mapping under loading. 30 human femoral osteochondral samples underwent imaging on a clinical 3.0 T MRI scanner (Achieva, Philips) in the unloaded reference configuration (δ0) and under pressure-controlled quasi-static indentation loading to 15.1 N (δ1) and to 28.6 N (δ2). Imaging was performed before and after exposure to low (LC, 0.5 mg/mL; n = 10) or high concentration (HC, 1.5 mg/mL; n = 10) of collagenase. Untreated samples served as controls (n = 10). Loading responses were determined for the entire sample and the directly loaded (i.e. sub-pistonal) and bilaterally adjacent (i.e. peri‑pistonal) regions, referenced histologically, quantified as relative changes, and analysed using adequate parametric and non-parametric statistical tests. Dose-dependant surface disintegration and tissue loss were reflected by distinctly different pre- and post-exposure response-to-loading patterns. While T1 generally decreased with loading, regardless of collagenase exposure, T1ρ increased significantly after HC exposure (p = 0.008). Loading-induced decreases in T2 were significant after LC exposure (p = 0.006), while changes in T2* were ambiguous. In conclusion, aberrant loading-induced changes in T2 and T1ρ reflect moderate and severe matrix changes, respectively, and indicate the close interrelatedness of matrix changes and functionality in cartilage.
Collapse
Affiliation(s)
- Tobias Hafner
- Aachen University Hospital, Department of Diagnostic and Interventional Radiology,D-52074 Aachen, Germany
| | - Manuel Post
- Aachen University Hospital, Department of Diagnostic and Interventional Radiology,D-52074 Aachen, Germany
| | - Oliver Said
- Aachen University Hospital, Department of Diagnostic and Interventional Radiology,D-52074 Aachen, Germany
| | - Philipp Schad
- Aachen University Hospital, Department of Diagnostic and Interventional Radiology,D-52074 Aachen, Germany
| | - Justus Schock
- University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany; Institute of Computer Vision and Imaging, RWTH University Aachen, D-52074 Aachen, Germany
| | - Daniel Benjamin Abrar
- University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany
| | - Matthias Knobe
- Clinic for Orthopaedic and Trauma Surgery, Cantonal Hospital Luzern, CH-6004 Luzern, Switzerland
| | - Christiane Kuhl
- Aachen University Hospital, Department of Diagnostic and Interventional Radiology,D-52074 Aachen, Germany
| | - Daniel Truhn
- Aachen University Hospital, Department of Diagnostic and Interventional Radiology,D-52074 Aachen, Germany
| | - Sven Nebelung
- University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany.
| |
Collapse
|
3
|
Hafner T, Schock J, Post M, Abrar DB, Sewerin P, Linka K, Knobe M, Kuhl C, Truhn D, Nebelung S. A serial multiparametric quantitative magnetic resonance imaging study to assess proteoglycan depletion of human articular cartilage and its effects on functionality. Sci Rep 2020; 10:15106. [PMID: 32934341 PMCID: PMC7492285 DOI: 10.1038/s41598-020-72208-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/21/2020] [Indexed: 02/06/2023] Open
Abstract
Water, collagen, and proteoglycans determine articular cartilage functionality. If altered, susceptibility to premature degeneration is increased. This study investigated the effects of enzymatic proteoglycan depletion on cartilage functionality as assessed by advanced Magnetic Resonance Imaging (MRI) techniques under standardized loading. Lateral femoral condylar cartilage-bone samples from patients undergoing knee replacement (n = 29) were serially imaged by Proton Density-weighted and T1, T1ρ, T2, and T2* mapping sequences on a clinical 3.0 T MRI scanner (Achieva, Philips). Using pressure-controlled indentation loading, samples were imaged unloaded and quasi-statically loaded to 15.1 N and 28.6 N, and both before and after exposure to low-concentrated (LT, 0.1 mg/mL, n = 10) or high-concentrated trypsin (HT, 1.0 mg/mL, n = 10). Controls were not treated (n = 9). Responses to loading were assessed for the entire sample and regionally, i.e. sub- and peri-pistonally, and zonally, i.e. upper and lower sample halves. Trypsin effects were quantified as relative changes (Δ), analysed using appropriate statistical tests, and referenced histologically. Histological proteoglycan depletion was reflected by significant sub-pistonal decreases in T1 (p = 0.003) and T2 (p = 0.008) after HT exposure. Loading-induced changes in T1ρ and T2* were not related. In conclusion, proteoglycan depletion alters cartilage functionality and may be assessed using serial T1 and T2 mapping under loading.
Collapse
Affiliation(s)
- Tobias Hafner
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany
| | - Justus Schock
- Medical Faculty, Department of Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Moorenstraße 5, 40225, Dusseldorf, Germany.,Institute of Computer Vision and Imaging, RWTH University Aachen, Aachen, Germany
| | - Manuel Post
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany
| | - Daniel Benjamin Abrar
- Medical Faculty, Department of Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Moorenstraße 5, 40225, Dusseldorf, Germany
| | - Philipp Sewerin
- Medical Faculty, Department and Hiller-Research-Unit for Rheumatology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Kevin Linka
- Department of Continuum and Materials Mechanics, Hamburg University of Technology, Hamburg, Germany
| | - Matthias Knobe
- Clinic for Orthopaedic and Trauma Surgery, Cantonal Hospital Luzern, Luzern, Switzerland
| | - Christiane Kuhl
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany
| | - Daniel Truhn
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany
| | - Sven Nebelung
- Medical Faculty, Department of Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Moorenstraße 5, 40225, Dusseldorf, Germany.
| |
Collapse
|
4
|
Cai L, Nauman EA, Pedersen CBW, Neu CP. Finite deformation elastography of articular cartilage and biomaterials based on imaging and topology optimization. Sci Rep 2020; 10:7980. [PMID: 32409711 PMCID: PMC7224212 DOI: 10.1038/s41598-020-64723-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 04/17/2020] [Indexed: 01/17/2023] Open
Abstract
Tissues and engineered biomaterials exhibit exquisite local variation in stiffness that defines their function. Conventional elastography quantifies stiffness in soft (e.g. brain, liver) tissue, but robust quantification in stiff (e.g. musculoskeletal) tissues is challenging due to dissipation of high frequency shear waves. We describe new development of finite deformation elastography that utilizes magnetic resonance imaging of low frequency, physiological-level (large magnitude) displacements, coupled to an iterative topology optimization routine to investigate stiffness heterogeneity, including spatial gradients and inclusions. We reconstruct 2D and 3D stiffness distributions in bilayer agarose hydrogels and silicon materials that exhibit heterogeneous displacement/strain responses. We map stiffness in porcine and sheep articular cartilage deep within the bony articular joint space in situ for the first time. Elevated cartilage stiffness localized to the superficial zone is further related to collagen fiber compaction and loss of water content during cyclic loading, as assessed by independent T2 measurements. We additionally describe technical challenges needed to achieve in vivo elastography measurements. Our results introduce new functional imaging biomarkers, which can be assessed nondestructively, with clinical potential to diagnose and track progression of disease in early stages, including osteoarthritis or tissue degeneration.
Collapse
Affiliation(s)
- Luyao Cai
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, US
| | - Eric A Nauman
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, US
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47907, US
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, 47907, US
| | | | - Corey P Neu
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, US.
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, 80309, US.
| |
Collapse
|
5
|
Nebelung S, Post M, Knobe M, Shah D, Schleich C, Hitpass L, Kuhl C, Thüring J, Truhn D. Human articular cartilage mechanosensitivity is related to histological degeneration - a functional MRI study. Osteoarthritis Cartilage 2019; 27:1711-1720. [PMID: 31319176 DOI: 10.1016/j.joca.2019.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 06/13/2019] [Accepted: 07/03/2019] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate changes in response to sequential pressure-controlled loading and unloading in human articular cartilage of variable histological degeneration using serial T1ρ mapping. METHOD We obtained 42 cartilage samples of variable degeneration from the medial femoral condyles of 42 patients undergoing total knee replacement. Samples were placed in a standardized artificial knee joint within an MRI-compatible whole knee-joint compressive loading device and imaged before (δ0), during (δld1, δld2, δld3, δld4, δld5) and after (δrl1, δrl2, δrl3, δrl4, δrl5) pressure-controlled loading to 0.663 ± 0.021 kN (94% body weight) using serial T1ρ mapping (spin-lock multigradient echo sequence; 3.0T MRI system [Achieva, Philips]). Reference assessment included histology (Mankin scoring) and conventional biomechanics (Tangent stiffness). We dichotomized sample into intact (n = 21) and degenerative (n = 21) based on histology and analyzed data using Mann Whitney, Kruskal Wallis, one-way ANOVA tests and Spearman's correlation, respectively. RESULTS At δ0, we found no significant differences between intact and degenerative samples, while the response-to-loading patterns were distinctly different. In intact samples, T1ρ increases were consistent and non-significant, while in degenerative samples, T1ρ increases were significantly higher (P = 0.004, δ0 vs δld1, δ0 vs δld3), yet undulating and variable. With unloading, T1ρ increases subsided, yet were persistently elevated beyond δ0. CONCLUSION Cartilage mechanosensitivity is related to histological degeneration and assessable by serial T1ρ mapping. Unloaded, T1ρ characteristics are not significantly different in intact vs degenerative cartilage, while load bearing is organized in intact cartilage and disorganized in degenerative cartilage.
Collapse
Affiliation(s)
- S Nebelung
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| | - M Post
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| | - M Knobe
- Department of Orthopaedic Trauma, Aachen University Hospital, Aachen, Germany.
| | - D Shah
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| | - C Schleich
- Department of Diagnostic and Interventional Radiology, University of Düsseldorf, Düsseldorf, Germany.
| | - L Hitpass
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| | - C Kuhl
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| | - J Thüring
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| | - D Truhn
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany; Institute of Imaging and Computer Vision, RWTH Aachen University, Aachen, Germany.
| |
Collapse
|
6
|
A multi-purpose force-controlled loading device for cartilage and meniscus functionality assessment using advanced MRI techniques. J Mech Behav Biomed Mater 2019; 101:103428. [PMID: 31604169 DOI: 10.1016/j.jmbbm.2019.103428] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 07/19/2019] [Accepted: 09/10/2019] [Indexed: 12/12/2022]
Abstract
Response to loading of soft tissues as assessed by advanced magnetic resonance imaging (MRI) techniques is a promising approach to evaluate tissue functionality beyond (statically obtained) structural and compositional features. As cartilage and meniscus pathologies are closely intertwined in osteoarthritis (OA) and beyond, both tissues should ideally be studied to elucidate further the underlying mechanisms involved in load transmission and its failure leading to OA. Hence, we devised, constructed and validated a dedicated MRI-compatible pneumatic force-controlled loading device to study cartilage and meniscus functionality in a standardized and reproducible manner and in reference to alternative tissue evaluation methods. Mechanical reference measurements using digital force sensors confirmed the reproducible application of forces in the range of 0-76N. To demonstrate the device's utility in a basic research context, MRI measurements of human articular cartilage (obtained from the lateral femoral condyle, n = 5) and meniscus (obtained from lateral meniscus body, n = 5) were performed in the unloaded (δ0) and loaded configurations (δ1: [cartilage] 0.75 bar corresponding to 15.1 N, [meniscus] 2 bar corresponding to 37.1 N; δ2: [cartilage] 1.5 bar corresponding to 28.6 N, [meniscus] 4 bar corresponding to 69.1 N). Cartilage samples were directly indented, while meniscus samples were subject to torque-induced compression using a dedicated lever compression device. Morphological MR Imaging using Proton Density-weighted sequences and quantitative MR Imaging using T2 and T1ρ mapping were performed serially and at high resolution. For reference, samples underwent subsequent biomechanical and histological reference evaluation. In conclusion, the force-controlled loading device has been validated for the non-invasive response-to-loading assessment of human cartilage and meniscus samples by advanced MRI techniques. Hereby, both tissues may be functionally evaluated in combination, beyond mere static analysis and in reference to histological and biomechanical measures.
Collapse
|
7
|
Differentiation of human cartilage degeneration by functional MRI mapping—an ex vivo study. Eur Radiol 2019; 29:6671-6681. [DOI: 10.1007/s00330-019-06283-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 04/25/2019] [Accepted: 05/22/2019] [Indexed: 12/26/2022]
|
8
|
Lange T, Taghizadeh E, Knowles BR, Südkamp NP, Zaitsev M, Meine H, Izadpanah K. Quantification of patellofemoral cartilage deformation and contact area changes in response to static loading via high-resolution MRI with prospective motion correction. J Magn Reson Imaging 2019; 50:1561-1570. [PMID: 30903682 DOI: 10.1002/jmri.26724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/26/2019] [Accepted: 02/26/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Higher-resolution MRI of the patellofemoral cartilage under loading is hampered by subject motion since knee flexion is required during the scan. PURPOSE To demonstrate robust quantification of cartilage compression and contact area changes in response to in situ loading by means of MRI with prospective motion correction and regularized image postprocessing. STUDY TYPE Cohort study. SUBJECTS Fifteen healthy male subjects. FIELD STRENGTH 3 T. SEQUENCE Spoiled 3D gradient-echo sequence augmented with prospective motion correction based on optical tracking. Measurements were performed with three different loads (0/200/400 N). ASSESSMENT Bone and cartilage segmentation was performed manually and regularized with a deep-learning approach. Average patellar and femoral cartilage thickness and contact area were calculated for the three loading situations. Reproducibility was assessed via repeated measurements in one subject. STATISTICAL TESTS Comparison of the three loading situations was performed by Wilcoxon signed-rank tests. RESULTS Regularization using a deep convolutional neural network reduced the variance of the quantified relative load-induced changes of cartilage thickness and contact area compared to purely manual segmentation (average reduction of standard deviation by ∼50%) and repeated measurements performed on the same subject demonstrated high reproducibility of the method. For the three loading situations (0/200/400 N), the patellofemoral cartilage contact area as well as the mean patellar and femoral cartilage thickness were significantly different from each other (P < 0.05). While the patellofemoral cartilage contact area increased under loading (by 14.5/19.0% for loads of 200/400 N), patellar and femoral cartilage thickness exhibited a load-dependent thickness decrease (patella: -4.4/-7.4%, femur: -3.4/-7.1% for loads of 200/400 N). DATA CONCLUSION MRI with prospective motion correction enables quantitative evaluation of patellofemoral cartilage deformation and contact area changes in response to in situ loading. Regularizing the manual segmentations using a neural network enables robust quantification of the load-induced changes. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1561-1570.
Collapse
Affiliation(s)
- Thomas Lange
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Elham Taghizadeh
- Medical Image Computing Group, Department of Informatics, University of Bremen, Germany.,Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Benjamin R Knowles
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Norbert P Südkamp
- Department of Orthopedic and Trauma Surgery, Medical Center - Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Freiburg im Breisgau, Germany
| | - Maxim Zaitsev
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Hans Meine
- Medical Image Computing Group, Department of Informatics, University of Bremen, Germany.,Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Kaywan Izadpanah
- Department of Orthopedic and Trauma Surgery, Medical Center - Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Freiburg im Breisgau, Germany
| |
Collapse
|
9
|
Nebelung S, Sondern B, Jahr H, Tingart M, Knobe M, Thüring J, Kuhl C, Truhn D. Non-invasive T1ρ mapping of the human cartilage response to loading and unloading. Osteoarthritis Cartilage 2018; 26:236-244. [PMID: 29175373 DOI: 10.1016/j.joca.2017.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 09/21/2017] [Accepted: 11/13/2017] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To define the physiological response to sequential loading and unloading in histologically intact human articular cartilage using serial T1ρ mapping, as T1ρ is considered to indicate the tissue's macromolecular content. METHOD 18 macroscopically intact cartilage-bone samples were obtained from the central lateral femoral condyles of 18 patients undergoing total knee replacement. Serial T1ρ mapping was performed on a clinical 3.0-T MRI system using a modified prostate coil. Spin-lock multiple gradient-echo sequences prior to, during and after standardized indentation loading (displacement controlled, strain 20%) were used to obtain seven serial T1ρ maps: unloaded (δ0), quasi-statically loaded (indentation1-indentation3) and under subsequent relaxation (relaxation1-relaxation3). After manual segmentation, zonal and regional regions-of-interest were defined. ROI-specific relative changes were calculated and statistically assessed using paired t-tests. Histological (Mankin classification) and biomechanical (unconfined compression) evaluations served as references. RESULTS All samples were histologically and biomechanically grossly intact (Mankin sum: 1.8 ± 1.2; Young's Modulus: 0.7 ± 0.4 MPa). Upon loading, T1ρ consistently increased throughout the entire sample thickness, primarily subpistonally (indentation1 [M ± SD]: 9.5 ± 7.8% [sub-pistonal area, SPA] vs 4.2 ± 5.8% [peri-pistonal area, PPA]; P < 0.001). T1ρ further increased with ongoing loading (indentation3: 14.1 ± 8.1 [SPA] vs 7.7 ± 5.9% [PPA]; P < 0.001). Even upon unloading (i.e., relaxation), T1ρ persistently increased in time. CONCLUSION Serial T1ρ-mapping reveals distinct and complex zonal and regional changes in articular cartilage as a function of loading and unloading. Thereby, longitudinal adaptive processes in hyaline cartilage become evident, which may be used for the tissue's non-invasive functional characterization by T1ρ.
Collapse
Affiliation(s)
- S Nebelung
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| | - B Sondern
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| | - H Jahr
- Department of Orthopaedics, Aachen University Hospital, Aachen, Germany.
| | - M Tingart
- Department of Orthopaedics, Aachen University Hospital, Aachen, Germany.
| | - M Knobe
- Department of Orthopaedic Trauma, Aachen University Hospital, Aachen, Germany.
| | - J Thüring
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| | - C Kuhl
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| | - D Truhn
- Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
| |
Collapse
|
10
|
Lange T, Knowles BR, Herbst M, Izadpanah K, Zaitsev M. Comparative T
2
and T
1ρ
mapping of patellofemoral cartilage under in situ mechanical loading with prospective motion correction. J Magn Reson Imaging 2017; 46:452-460. [DOI: 10.1002/jmri.25574] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/17/2016] [Indexed: 11/11/2022] Open
Affiliation(s)
- Thomas Lange
- Department of Radiology, Medical Physics; Medical Center - University of Freiburg, Faculty of Medicine; Freiburg Germany
| | - Benjamin R. Knowles
- Department of Radiology, Medical Physics; Medical Center - University of Freiburg, Faculty of Medicine; Freiburg Germany
| | - Michael Herbst
- Department of Radiology, Medical Physics; Medical Center - University of Freiburg, Faculty of Medicine; Freiburg Germany
- John A. Burns School of Medicine; University of Hawaii; Honolulu Hawaii USA
| | - Kaywan Izadpanah
- Department of Orthopedic and Trauma Surgery; Medical Center - University of Freiburg, Faculty of Medicine; Freiburg Germany
| | - Maxim Zaitsev
- Department of Radiology, Medical Physics; Medical Center - University of Freiburg, Faculty of Medicine; Freiburg Germany
| |
Collapse
|
11
|
Load distribution in early osteoarthritis. Knee Surg Sports Traumatol Arthrosc 2016; 24:1815-25. [PMID: 27085358 DOI: 10.1007/s00167-016-4123-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/29/2016] [Indexed: 01/30/2023]
Abstract
Total knee replacement is an accepted standard of care for the treatment of advanced knee osteoarthritis with good results in the vast majority of older patients. The use in younger and more active populations, however, remains controversial due to concerns over activity restrictions, implant survival, and patient satisfaction with the procedure. It is in these younger patient populations that alternatives to arthroplasty are increasingly being explored. Historically, osteotomy was utilized to address unicompartmental pain from degeneration and overload, for example, after meniscectomy. Utilization rates of osteotomy have fallen in recent years due to the increasing popularity of partial and total knee arthroplasty. This article explores the indications and outcomes of traditional unloading osteotomy, as well as newer options that are less invasive and offer faster return to function.
Collapse
|
12
|
Lange T, Maclaren J, Herbst M, Lovell-Smith C, Izadpanah K, Zaitsev M. Knee cartilage MRI with in situ mechanical loading using prospective motion correction. Magn Reson Med 2016; 71:516-23. [PMID: 23440894 DOI: 10.1002/mrm.24679] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
PURPOSE To assess the feasibility of high resolution knee cartilage MRI with in situ mechanical loading using optical tracking to compensate for motion. METHODS In vivo cartilage MRI with in situ mechanical loading is demonstrated on a clinical 3T system for the patellofemoral as well as for the tibiofemoral knee joint using a T1-weighted spoiled three-dimensional gradient-echo sequence. Prospective motion correction is performed with a moiré phase tracking system consisting of an in-bore camera and a single tracking marker attached to the skin. RESULTS Rigid-body approximation required for prospective correction with optical motion tracking is fulfilled well enough for the patellofemoral as well as for the tibiofemoral joint when the tracking marker is attached to the knee cap and the shin, respectively. Presaturation proves to be efficient in suppressing pulsation artifacts from the popliteal artery and residual motion artifacts primarily arising from nonrigid motion of the posterior knee compartment. CONCLUSION The proposed technique enables knee cartilage imaging under in situ mechanical loading with submillimeter spatial resolution devoid of significant motion artifacts and thus appropriate for cartilage volumetry. It has the potential to provide new insight into the biomechanics of the knee and might complement the panoply of diagnostic MR methods for osteoarthritis.
Collapse
Affiliation(s)
- Thomas Lange
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany
| | | | | | | | | | | |
Collapse
|
13
|
Comparison of load responsiveness of cartilage T1rho and T2 in porcine knee joints: an experimental loading MRI study. Osteoarthritis Cartilage 2015; 23:1776-9. [PMID: 26028138 DOI: 10.1016/j.joca.2015.05.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 05/06/2015] [Accepted: 05/21/2015] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To compare changes in T1rho and T2 values of the femoral cartilage in porcine knee joints under staged loading and unloading conditions. DESIGN Sixteen porcine knee joints with intact capsules and surrounding muscle were imaged using a custom-made pressure device and 3.0 T magnetic resonance imaging. Sagittal T1rho and T2 images were obtained for the lateral and medial condyles under the following compression loads: none (Load 0), 140 N (Load 140), 300 N (Load 300), and no compression after decompression (Post-load). The percentage changes of cartilage T1rho and T2 values under each loading condition from those at Load 0 were calculated for weight-bearing overall and eight subdivided regions of interest (ROIs) in both femoral condyles. The actual contact pressure under Load 140 and Load 300 was measured using pressure-sensitive film. RESULTS For the overall ROI, the mean decreases of T1rho and T2 values were 4.4% and 5.1% under Load 140% and 10.9% and 10.6% under Load 300 in the medial condyle and were 5.2% and 4.0% under Load 140% and 10.6% and 6.0% under Load 300 in the lateral condyle. In the medial condyle, the actual contact pressure correlated highly with percentage changes in T1rho (r = -0.84, P < 0.01) and T2 (r = -0.79, P < 0.01), but those correlations were relatively low in the lateral condyle. CONCLUSION Although there were side-dependent variations in the correlations with actual pressure, cartilage T1rho and T2 showed similarly sensitive responses to applied load.
Collapse
|
14
|
Orsi AD, Chakravarthy S, Canavan PK, Peña E, Goebel R, Vaziri A, Nayeb-Hashemi H. The effects of knee joint kinematics on anterior cruciate ligament injury and articular cartilage damage. Comput Methods Biomech Biomed Engin 2015; 19:493-506. [PMID: 26068032 DOI: 10.1080/10255842.2015.1043626] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This study determined which knee joint motions lead to anterior cruciate ligament (ACL) rupture with the knee at 25° of flexion. The knee was subjected to internal and external rotations, as well as varus and valgus motions. A failure locus representing the relationship between these motions and ACL rupture was established using finite element simulations. This study also considered possible concomitant injuries to the tibial articular cartilage prior to ACL injury. The posterolateral bundle of the ACL demonstrated higher rupture susceptibility than the anteromedial bundle. The average varus angular displacement required for ACL failure was 46.6% lower compared to the average valgus angular displacement. Femoral external rotation decreased the frontal plane angle required for ACL failure by 27.5% compared to internal rotation. Tibial articular cartilage damage initiated prior to ACL failure in all valgus simulations. The results from this investigation agreed well with other experimental and analytical investigations. This study provides a greater understanding of the various knee joint motion combinations leading to ACL injury and articular cartilage damage.
Collapse
Affiliation(s)
- Alexander D Orsi
- a Biomechanics Research Group, 334 Snell Engineering Center, Northeastern University , 360 Huntington Avenue, Boston , MA , USA
| | - Srinath Chakravarthy
- a Biomechanics Research Group, 334 Snell Engineering Center, Northeastern University , 360 Huntington Avenue, Boston , MA , USA
| | - Paul K Canavan
- b Hartford HealthCare Rehabilitation Network , 230 Main St, Manchester , CT , USA
| | - Estefanía Peña
- c Bioengineering Division, Aragon Institute of Engineering Research, University of Zaragoza, CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) , Zaragoza , Spain
| | - Ruben Goebel
- d Sport Science Program, Qatar University , Doha , Qatar
| | - Askhan Vaziri
- a Biomechanics Research Group, 334 Snell Engineering Center, Northeastern University , 360 Huntington Avenue, Boston , MA , USA
| | - Hamid Nayeb-Hashemi
- a Biomechanics Research Group, 334 Snell Engineering Center, Northeastern University , 360 Huntington Avenue, Boston , MA , USA
| |
Collapse
|
15
|
Khalilzad-Sharghi V, Han Z, Xu H, Othman SF. MR elastography for evaluating regeneration of tissue-engineered cartilage in an ectopic mouse model. Magn Reson Med 2015; 75:1209-17. [PMID: 25918870 DOI: 10.1002/mrm.25745] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 03/30/2015] [Accepted: 03/31/2015] [Indexed: 12/20/2022]
Abstract
PURPOSE The purpose of the present study was to apply noninvasive methods for monitoring regeneration and mechanical properties of tissue-engineered cartilage in vivo at different growth stages using MR elastography (MRE). METHODS Three types of scaffolds, including silk, collagen, and gelatin seeded by human mesenchymal stem cells, were implanted subcutaneously in mice and imaged at 9.4T where the shear stiffness and transverse MR relaxation time (T2 ) were measured for the regenerating constructs for 8 wk. An MRE phase contrast spin echo-based sequence was used for collecting MRE images. At the conclusion of the in vivo study, constructs were excised and transcript levels of cartilage-specific genes were quantitated using reverse-transcription polymerase chain reaction. RESULTS Tissue-engineered constructs showed a cartilage-like construct with progressive tissue formation characterized by increase in shear stiffness and decrease in T2 that can be correlated with increased cartilage transcript levels including aggrecan, type II collagen, and cartilage oligomeric matrix protein after 8 wk of in vivo culture. CONCLUSION Altogether, the outcome of this research demonstrates the feasibility of MRE and MRI for noninvasive monitoring of engineered cartilage construct's growth after implantation and provides noninvasive biomarkers for regeneration, which may be translated into treatment of tissue defects.
Collapse
Affiliation(s)
- Vahid Khalilzad-Sharghi
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Zhongji Han
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Huihui Xu
- School of Engineering and Computer Science, University of the Pacific, Stockton, California, USA
| | - Shadi F Othman
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| |
Collapse
|
16
|
Wang N, Kahn D, Badar F, Xia Y. Molecular origin of a loading-induced black layer in the deep region of articular cartilage at the magic angle. J Magn Reson Imaging 2014; 41:1281-90. [PMID: 24833266 DOI: 10.1002/jmri.24658] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 04/22/2014] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To investigate the molecular origin of an unusual low-intensity layer in the deep region of articular cartilage as seen in magnetic resonance imaging (MRI) when the tissue is imaged under compression and oriented at the magic angle. MATERIALS AND METHODS Microscopic MRI (μMRI) T2 and T1 ρ experiments were carried out on 18 specimens, both native and degraded (treated with trypsin). The glycosaminoglycan (GAG) concentrations in the specimens were quantified by both sodium ICP-OES and μMRI Gd(DTPA)(2-) -contrast methods. The mechanical modulus of the specimens was also measured. RESULTS Native tissue shows no load-induced layer, while the trypsin-degraded tissue shows clearly the low-intensity line at the deep part of tissue. The GAG reductions were confirmed by the sodium ICP-OES (from 81.7 ± 5.4 mg/mL to 9.2 ± 3.4 mg/mL), MRI GAG quantification (from 72.4 ± 6.7 mg/mL to 11.2 ± 2.9 mg/mL). The modulus reduction was confirmed by biomechanics (from 4.3 ± 0.7 MPa to 0.3 ± 0.1 MPa). CONCLUSION Both T2 and T1 ρ profiles in native and degraded cartilage show strongly strain-, depth-, and angle-dependence using high-resolution MRI. The GAG reduction is responsible for the visualization of a low-intensity layer in deep cartilage when it is loaded and oriented at 55°.
Collapse
Affiliation(s)
- Nian Wang
- Department of Physics and Center for Biomedical Research, Oakland University, Rochester, Michigan, USA
| | | | | | | |
Collapse
|
17
|
Markhardt BK, Chang EY. Hypointense signal lesions of the articular cartilage: a review of current concepts. Clin Imaging 2014; 38:785-91. [PMID: 24928821 DOI: 10.1016/j.clinimag.2014.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 05/04/2014] [Indexed: 11/28/2022]
Abstract
Discussion of articular cartilage disease detection by MRI usually focuses on the presence of bright signal on T2-weighted sequences, such as in Grade 1 chondromalacia and cartilage fissures containing fluid. Less emphasis has been placed on how cartilage disease may be manifested by dark signal on T2-weighted sequences. The appearance of the recently described "cartilage black line sign" of the femoral trochlea highlights these lesions and further raises the question of their etiology. We illustrate various hypointense signal lesions that are not restricted to the femoral trochlea of the knee joint and discuss the possible etiologies for these lesions.
Collapse
Affiliation(s)
- B Keegan Markhardt
- Department of Radiology, Community Division, University of Wisconsin, Madison, WI.
| | - Eric Y Chang
- Department of Radiology, VA San Diego Healthcare System, San Diego, CA; Department of Radiology, University of California, San Diego Medical Center, San Diego, CA.
| |
Collapse
|
18
|
Schiller J, Huster D. New methods to study the composition and structure of the extracellular matrix in natural and bioengineered tissues. BIOMATTER 2014; 2:115-31. [PMID: 23507863 PMCID: PMC3549865 DOI: 10.4161/biom.20866] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The extracellular matrix (ECM) comprises a gel of numerous biopolymers that occurs in a multitude of biological tissues. The ECM provides the basic support and mechanical strength of skeletal tissue and is responsible for shape retention. At the same time, the ECM is responsible for the viscoelastic properties and the elasticity of soft tissues. As expected, there are several important diseases that affect and degenerate the ECM with severe consequences for its properties. Bioengineering is a promising approach to support the regenerative capacity of the body. Unfortunately, the biomechanical properties of bioengineered ECM often only poorly meet the standards of their native counterparts. Many bioengineered tissues are characterized by an increased glycosaminoglycan (GAG) but decreased collagen content. This leads to an enhanced water content that strongly alters the viscoelastic and thus the biomechanical properties. Therefore, compositional analysis is important to estimate the tissue quality. We will show that nuclear magnetic resonance (NMR) spectroscopy and soft-ionization mass spectrometry (MS) represent useful techniques for ECM research both in natural and bioengineered tissues. Both methods are strongly complimentary: while MS techniques such as matrix-assisted laser desorption and ionization (MALDI) are excellent and very sensitive analytical tools to determine the collagen and the GAG contents of tissues, NMR spectroscopy provides insight into the molecular architecture of the ECM, its dynamics and other important parameters such as the water content of the tissue as well as the diffusion of molecules within the ECM.
Collapse
Affiliation(s)
- Jürgen Schiller
- University of Leipzig, Medical Faculty, Institute of Medical Physics and Biophysics, Leipzig, Germany.
| | | |
Collapse
|
19
|
Garnov N, Gründer W, Thörmer G, Trampel R, Turner R, Kahn T, Busse H. In vivo MRI analysis of depth-dependent ultrastructure in human knee cartilage at 7 T. NMR IN BIOMEDICINE 2013; 26:1412-1419. [PMID: 23801556 DOI: 10.1002/nbm.2968] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 02/26/2013] [Accepted: 04/01/2013] [Indexed: 06/02/2023]
Abstract
Signal intensities of T2-weighted magnetic resonance images depend on the local fiber arrangement in hyaline cartilage. The aims of this study were to determine whether angle-sensitive MRI at 7 T can be used to quantify the cartilage ultrastructure of the knee in vivo and to assess potential differences with age. Ten younger (21-30) and ten older (55-76 years old) healthy volunteers were imaged with a T2-weighted spin-echo sequence in a 7 T whole-body MRI. A "fascicle" model was assumed to describe the depth-dependent fiber arrangement of cartilage. The R/T boundary positions between radial and transitional zones were assessed from intensity profiles in small regions of interest in the femur and tibia, and normalized to cartilage thickness using logistic curve fits. The quality of our highly resolved (0.3 × 0.3 × 1.0 mm(3)) MR cartilage images were high enough for quantitative analysis (goodness of fit R(2) = 0.91 ± 0.09). Between younger and older subjects, normalized positions of the R/T boundary, with value 0 at the bone-cartilage interface and 1 at the cartilage surface, were significantly (p < 0.05) different in femoral (0.51 ± 0.12 versus 0.41 ± 0.10), but not in tibial cartilage (0.65 ± 0.11 versus 0.57 ± 0.09, p = 0.119). Within both age groups, differences between femoral and tibial R/T boundaries were significant. Using a fascicle model and angle-sensitive MRI, the depth-dependent anisotropic fiber arrangement of knee cartilage could be assessed in vivo from a single 7 T MR image. The derived quantitative parameter, thickness of the radial zone, may serve as an indicator of the structural integrity of cartilage. This method may potentially be suitable to detect and monitor early osteoarthritis because the progressive disintegration of the anisotropic network is also indicative of arthritic changes in cartilage.
Collapse
Affiliation(s)
- Nikita Garnov
- Department of Diagnostic and Interventional Radiology, Leipzig University Hospital, Liebigstrasse 20, Leipzig, Germany
| | | | | | | | | | | | | |
Collapse
|
20
|
Palmer AJR, Brown CP, McNally EG, Price AJ, Tracey I, Jezzard P, Carr AJ, Glyn-Jones S. Non-invasive imaging of cartilage in early osteoarthritis. Bone Joint J 2013; 95-B:738-46. [PMID: 23723266 DOI: 10.1302/0301-620x.95b6.31414] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Treatment for osteoarthritis (OA) has traditionally focused on joint replacement for end-stage disease. An increasing number of surgical and pharmaceutical strategies for disease prevention have now been proposed. However, these require the ability to identify OA at a stage when it is potentially reversible, and detect small changes in cartilage structure and function to enable treatment efficacy to be evaluated within an acceptable timeframe. This has not been possible using conventional imaging techniques but recent advances in musculoskeletal imaging have been significant. In this review we discuss the role of different imaging modalities in the diagnosis of the earliest changes of OA. The increasing number of MRI sequences that are able to non-invasively detect biochemical changes in cartilage that precede structural damage may offer a great advance in the diagnosis and treatment of this debilitating condition.
Collapse
Affiliation(s)
- A J R Palmer
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Windmill Road, Headington OX3 7LD, UK
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Garnov N, Busse H, Gründer W. Angle-sensitive MRI for quantitative analysis of fiber-network deformations in compressed cartilage. Magn Reson Med 2013; 70:225-31. [PMID: 23716388 DOI: 10.1002/mrm.24795] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 04/11/2013] [Accepted: 04/14/2013] [Indexed: 11/10/2022]
Abstract
PURPOSE To demonstrate the feasibility of a novel experimental method to quantitatively analyze fiber-network deformation in compressed cartilage by angle-sensitive magnetic resonance imaging (MRI) of cartilage. METHODS Three knee cartilage samples of an adult sheep were imaged in a high-resolution MRI scanner at 7 T. Main fiber orientation and its "offset" from the direction perpendicular to the bone-cartilage boundary were derived from MR images taken at different orientations with respect to B0. Bending of the collagen fibers was determined from weight-bearing MRI with the load (up to 1.0 MPa) applied over the whole sample surface. A "fascicle" model of the cartilage ultrastructure was assumed to analyze characteristic intensity variations in T2-weighted images under load. RESULTS T2-weighted MR images showed a strong variation of the signal intensities with sample orientation. In the T2-weighted weight-bearing series, regions of high signal intensity underwent shifts from the lateral to the central parts in all three cartilage samples. The bending of the collagen fibers was determined to be 27.2°, 35.4°, and 40.0° per MPa, respectively. CONCLUSION Assuming a "fascicle" model, the presented MRI method provides quantitative measures of structural adjustments in compressed cartilage. Our preliminary analysis suggests that cartilage fiber deformation includes both bending and crimping.
Collapse
Affiliation(s)
- Nikita Garnov
- Department of Diagnostic and Interventional Radiology Leipzig University Hospital Liebigstrasse 20 Leipzig Germany.
| | | | | |
Collapse
|
22
|
Duyn J. MR susceptibility imaging. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 229:198-207. [PMID: 23273840 PMCID: PMC3602381 DOI: 10.1016/j.jmr.2012.11.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 11/14/2012] [Accepted: 11/15/2012] [Indexed: 05/23/2023]
Abstract
This work reviews recent developments in the use of magnetic susceptibility contrast for human MRI, with a focus on the study of brain anatomy. The increase in susceptibility contrast with modern high field scanners has led to novel applications and insights into the sources and mechanism contributing to this contrast in brain tissues. Dedicated experiments have demonstrated that in most of healthy brain, iron and myelin dominate tissue susceptibility variations, although their relative contribution varies substantially. Local variations in these compounds can affect both amplitude and frequency of the MRI signal. In white matter, the myelin sheath introduces an anisotropic susceptibility that has distinct effects on the water compartments inside the axons, between the myelin sheath, and the axonal space, and renders their signals dependent on the angle between the axon and the magnetic field. This offers opportunities to derive tissue properties specific to these cellular compartments.
Collapse
Affiliation(s)
- Jeff Duyn
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
23
|
Loading of the knee during 3.0T MRI is associated with significantly increased medial meniscus extrusion in mild and moderate osteoarthritis. Eur J Radiol 2013; 81:1839-45. [PMID: 21684704 DOI: 10.1016/j.ejrad.2011.05.027] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 05/09/2011] [Accepted: 05/10/2011] [Indexed: 11/24/2022]
Abstract
PURPOSE Standard knee MRI is performed under unloading (ULC) conditions and not much is known about changes of the meniscus, ligaments or cartilage under loading conditions (LC). The aim is to study the influence of loading of different knee structures at 3Tesla (T) in subjects with osteoarthritis (OA) and normal controls. MATERIALS AND METHODS 30 subjects, 10 healthy and 20 with radiographic evidence of OA (10 mild and 10 moderate) underwent 3T MRI under ULC and LC at 50% body weight. All images were analyzed by two musculoskeletal radiologists identifying and grading cartilage, meniscal, ligamentous abnormalities. The changes between ULC and LC were assessed. For meniscus, cartilage and ligaments the changes of lesions, signal and shape were evaluated. In addition, for the meniscus changes in extrusion were examined. A multivariate regression model was used for correlations to correct the data for the impact of age, gender, BMI. A paired T-Test was performed to calculate the differences in meniscus extrusion. RESULTS Subjects with degenerative knee abnormalities demonstrated significantly increased meniscus extrusion under LC when compared to normal subjects (p=0.0008-0.0027). Subjects with knee abnormalities and higher KL scores showed significantly more changes in lesion, signal and shape of the meniscus (80% (16/20) vs. 20% (2/10); p=0.0025), ligaments and cartilage during LC. CONCLUSION The study demonstrates that axial loading has an effect on articular cartilage, ligament, and meniscus morphology, which is more significant in subjects with degenerative disease and may serve as an additional diagnostic tool for disease diagnosis and assessing progression in subjects with knee OA.
Collapse
|
24
|
Influence of medial meniscectomy on stress distribution of the femoral cartilage in porcine knees: a 3D reconstructed T2 mapping study. Osteoarthritis Cartilage 2012; 20:1383-90. [PMID: 22846714 DOI: 10.1016/j.joca.2012.07.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 06/25/2012] [Accepted: 07/18/2012] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Previous studies have shown that meniscectomy results in an increase of local load transmission and may cause degeneration of the knee cartilage. Using 3D reconstructed T2 mapping, we examined the influence on the femoral cartilage under loading after medial meniscectomy. DESIGN Ten porcine knees were imaged using a pressure device and a 3.0-T magnetic resonance imaging (MRI) system. Consecutive sagittal T2 maps were obtained in neutral alignment with and without compression, and under compression at 10° varus alignment. After medial meniscectomy, the aforementioned MRI was repeated. Cartilage T2 before and after meniscectomy under each condition were compared at the 12 regions of interest (ROIs) defined on the 3D weight-bearing area of the femoral cartilage. RESULTS Before meniscectomy, large decreases in T2 under neutral compression were mainly seen at the anterior and central ROIs of the medial cartilage, which shifted to the posterior ROIs after meniscectomy. There were significant differences in decrease in T2 ratio with loading before and after meniscectomy (9.8%/4.3% at the anterior zone, 4.0%/11.4% at the posterior zone, P < 0.05). By applying varus compression, a more remarkable decrease in the cartilage T2 in posterior ROIs after meniscectomy was achieved. (Before/after meniscectomy: 8.7%/2.5% at the anterior zone, 7.2%/18.7% at the posterior zone, P < 0.05). CONCLUSIONS Assuming a decrease in T2 with loading correlated with the applied pressure, a deficiency of the medial meniscus resulted in a shift of the primary area with a maximal decrease of cartilage T2 with loading posteriorly in the porcine knee joint, presumably reflecting the intraarticular environment of load transmission.
Collapse
|
25
|
Seidel T, Hammer N, Garnov N, Schneider G, Steinke H. An algorithm for the calculation of three-dimensional collagen fiber orientation in ligaments using angle-sensitive MRI. Magn Reson Med 2012; 69:1595-602. [PMID: 22826018 DOI: 10.1002/mrm.24408] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 05/07/2012] [Accepted: 06/18/2012] [Indexed: 11/07/2022]
Abstract
A method based on angle-sensitive magnetic resonance imaging for determining unknown orientations of collagen fibers in ligaments is presented. Collagen fibers were stepwise rotated around two independent axes within a 3T magnetic resonance tomograph (from 0° to 180°, step size=10°). Analyzing the magnetic resonance signal intensity of each voxel as a function of the rotation angle, directions were calculated by means of a computational algorithm. The accuracy of the algorithm was validated using 1000 random test directions, revealing an average deviation of 4.4° (median±standard deviation: 2.7°±9°). Subsequently, the presented method was applied to three specimens of the human iliotibial tract mounted in different directions in a rotatable plastic box. Polarized light microscopy was used to verify parallel alignment of the collagen fibers in the three specimens. The calculated directions were compared with the directions of the specimens. Analyzing each voxel separately, average deviations (median±standard deviation) in the three specimens were: 11.2° (3.6°±20.4°), 12° (5°±24.1°), and 20.4° (8.7°±27°). If the magnetic resonance signal intensity of each voxel was averaged with the intensity of immediately neighboring voxels, average deviations (median±standard deviation) were 8.5° (3.6°±17.4°), 6.2° (0°±18°), and 9.2° (5°±19.2°). The presented method has the potential to be applied in situ to anatomical structures like cartilage, ligaments, tendons and fascia.
Collapse
Affiliation(s)
- Thomas Seidel
- Institute of Anatomy, University of Leipzig, and Department of Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany
| | | | | | | | | |
Collapse
|
26
|
Weber F, Böhme J, Scheidt HA, Gründer W, Rammelt S, Hacker M, Schulz-Siegmund M, Huster D. 31P and 13C solid-state NMR spectroscopy to study collagen synthesis and biomineralization in polymer-based bone implants. NMR IN BIOMEDICINE 2012; 25:464-75. [PMID: 22351643 DOI: 10.1002/nbm.1649] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 09/16/2010] [Accepted: 10/31/2010] [Indexed: 05/24/2023]
Abstract
A combination of solid-state NMR spectroscopy and MRI was used to evaluate the formation of extracellular matrix in poly(D,L-lactide-co-glycolide) (PLGA) bone implants. Porous PLGA scaffolds were implanted into rat tibiae and analysed after 2, 4 or 8 weeks. MRI clearly delineated the implants within the cancellous bone. Differences in the trabecular structure of the implanted material and native bone were demonstrated. In addition, implants were analyzed by solid-state NMR spectroscopy under magic angle spinning. (13)C NMR spectra showed the unambiguous signature of collagen formed in the scaffolds, but also the characteristic signals of the PLGA matrix, indicating that resorption was not complete after 8 weeks. Furthermore, (31)P NMR spectroscopy detected the inorganic component of the matrix, which is composed of bioapatite. (31)P NMR spectra were quantified and this analysis revealed that the amount of inorganic extracellular matrix formed de novo was significantly lower than in native bone. This demonstrates that solid-state NMR spectroscopy, in particular in combination with MRI, can provide useful information on the composition and structure of the extracellular matrix, and serve as a tool to evaluate the quality of tissue engineering strategies.
Collapse
Affiliation(s)
- Franziska Weber
- Institute of Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Damion RA, Pawaskar SS, Ries ME, Ingham E, Williams S, Jin Z, Radjenovic A. Spin-lattice relaxation rates and water content of freeze-dried articular cartilage. Osteoarthritis Cartilage 2012; 20:184-90. [PMID: 22197886 DOI: 10.1016/j.joca.2011.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 11/14/2011] [Accepted: 12/12/2011] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Nuclear magnetic resonance (NMR) spin-lattice relaxation rates were measured in bovine and porcine articular cartilage as a function of water content. METHODS Water content was varied by freeze-drying samples for short periods of time (up to 15 min). The samples were weighed at all stages of drying so that water content could be quantified. Spin-lattice relaxation rates were measured using magnetic resonance imaging (MRI). RESULTS Linear correlations were observed between relaxation rate and two measures of inverse water content: (1) solid-to-water ratio (ρ), expressed as a ratio of the mass of the solid component of the cartilage (m(s)) and the mass of water at each freeze-drying time point (m(w)), and (2) a ratio of the total mass of the fully-hydrated cartilage and m(w) (1/w). These correlations did not appear significantly different for the bovine and porcine data. However, fitting the data to a piecewise-linear model revealed differences between these two species. We interpret the first two segments of the piecewise model as the depletion of different water phases but conjecture that the third segment is partially caused by changes in relaxation rates as a result of a reduction in macromolecular mobilities. CONCLUSIONS Whilst we can produce linear correlations which broadly describe the dependence of the measured spin-lattice relaxation rate on (inverse) water content, the linear model seems to obscure a more complicated relationship which potentially provides us with more information about the structure of articular cartilage and its extracellular water.
Collapse
Affiliation(s)
- R A Damion
- School of Physics & Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | | | | | | | | | | | | |
Collapse
|
28
|
Rössler E, Mattea C, Mollova A, Stapf S. Low-field one-dimensional and direction-dependent relaxation imaging of bovine articular cartilage. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 213:112-118. [PMID: 21962910 DOI: 10.1016/j.jmr.2011.09.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/01/2011] [Accepted: 09/06/2011] [Indexed: 05/31/2023]
Abstract
The structure of articular cartilage is separated into three layers of differently oriented collagen fibers, which is accompanied by a gradient of increasing glycosaminoglycan (GAG) and decreasing water concentration from the top layer towards the bone interface. The combined effect of these structural variations results in a change of the longitudinal and transverse relaxation times as a function of the distance from the cartilage surface. In this paper, this dependence is investigated at a magnetic field strength of 0.27 T with a one-dimensional depth resolution of 50 μm on bovine hip and stifle joint articular cartilage. By employing this method, advantage is taken of the increasing contrast of the longitudinal relaxation rate found at lower magnetic field strengths. Furthermore, evidence for an orientational dependence of relaxation times with respect to an axis normal to the surface plane is given, an observation that has recently been reported using high-field MRI and that was explained by preferential orientations of collagen bundles in each of the three cartilage zones. In order to quantify the extent of a further contrast mechanism and to estimate spatially dependent glycosaminoglycan concentrations, the data are supplemented by proton relaxation times that were acquired in bovine articular cartilage that was soaked in a 0.8 mM aqueous Gd++ solution.
Collapse
Affiliation(s)
- Erik Rössler
- Fachgebiet Technische Physik II/Polymerphysik, Institute of Physics, Technische Universität Ilmenau, PO Box 100 565, 98684 Ilmenau, Germany
| | | | | | | |
Collapse
|
29
|
Abstract
The newer magnetic resonance (MR) imaging methods can give insights into the initiation, progression, and eventual treatment of osteoarthritis. Sodium imaging is specific for changes in proteoglycan (PG) content without the need for an exogenous contrast agent. T1ρ imaging is sensitive to early PG depletion. Delayed gadolinium-enhanced MR imaging has high resolution and sensitivity. T2 mapping is straightforward and is sensitive to changes in collagen and water content. Ultrashort echo time MR imaging examines the osteochondral junction. Magnetization transfer provides improved contrast between cartilage and fluid. Diffusion-weighted imaging may be a valuable tool in postoperative imaging.
Collapse
|
30
|
Xia Y, Wang N, Lee J, Badar F. Strain-dependent T1 relaxation profiles in articular cartilage by MRI at microscopic resolutions. Magn Reson Med 2011; 65:1733-7. [PMID: 21452280 PMCID: PMC3097314 DOI: 10.1002/mrm.22933] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 02/28/2011] [Accepted: 03/02/2011] [Indexed: 11/11/2022]
Abstract
To investigate the dependency of T(1) relaxation on mechanical strain in articular cartilage, quantitative magnetic resonance T(1) imaging experiments were carried out on cartilage before/after the tissue was immersed in gadolinium contrast agent and when the tissue was being compressed (up to ∼ 48% strains). The spatial resolution across the cartilage depth was 17.6 μm. The T(1) profile in native tissue (without the presence of gadolinium ions) was strongly strain-dependent, which is also depth-dependent. At the modest strains (e.g., 14% strain), T(1) reduced by up to 68% in the most surface portion of the tissue. Further compression (e.g., 45% strain) reduced T(1) mostly in the middle and deep portions of the tissue. For the gadolinium-immersed tissue, both modest and heavy compressions (up to 48% strain) increased T(1) slightly but significantly, although the overall shapes of the T(1) profiles remained approximately the same regardless of the amount of strains. The complex relationships between the T(1) profiles and the mechanical strains were a direct consequence of the depth-dependent proteoglycan concentration in the tissue, which determined the tissue's mechanical properties. This finding has potential implications in the use of gadolinium contrast agent in clinical magnetic resonance imaging of cartilage (the dGEMRIC procedure), when the loading or loading history of patients is considered.
Collapse
Affiliation(s)
- Yang Xia
- Department of Physics and Center for Biomedical Research, Oakland University, Rochester, Michigan 48309, USA.
| | | | | | | |
Collapse
|
31
|
Shiomi T, Nishii T, Myoui A, Yoshikawa H, Sugano N. Influence of knee positions on T2, T*2, and dGEMRIC mapping in porcine knee cartilage. Magn Reson Med 2011; 64:707-14. [PMID: 20535811 DOI: 10.1002/mrm.22469] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We examined the influence of flexed knee positions on cartilage MR assessments. Sagittal T(2), T*(2), and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) maps of the femoral cartilage were obtained in eight 6-month-old porcine femorotibial joints in the extended knee position (position A: flexion 0 degrees and femoral shaft in parallel with the amplitude of static field), flexed knee position (position B: flexion 40 degrees and femoral shaft oriented at 40 degrees to the amplitude of static field), and oblique-placed knee-extended position (position C: flexion 0 degrees and femoral shaft oriented at 40 degrees to the amplitude of static field). Comparison of the MR parameters between positions A and C showed isolated influence of the magic-angle effect, and comparison between positions A and B showed effects of knee flexion. Proteoglycan and hydroxyproline content in cartilage specimen at each region of interest had no significant correlation with T(2), T*(2), and dGEMRIC values. At the central zone, located on a weight-bearing area and parallel to the amplitude of static field, T(2)/T*(2)/dGEMRIC values increased by 6.8/11/0.8% at position C and by 24/44/31% at position B compared with position A. There was a significant increase in T(2) and T*(2) values at position B compared with those at position A. The substantial changes in T(2), T*(2), and dGEMRIC were shown in response to knee flexion, presumably due to the compounding influence of the magic-angle effect and change in the intra-articular biomechanical condition.
Collapse
Affiliation(s)
- Toshiyuki Shiomi
- Department of Orthopaedic Surgery, Osaka University Medical School, Osaka, Japan
| | | | | | | | | |
Collapse
|
32
|
Nishii T, Shiomi T, Tanaka H, Yamazaki Y, Murase K, Sugano N. Loaded Cartilage T2 Mapping in Patients with Hip Dysplasia. Radiology 2010; 256:955-65. [DOI: 10.1148/radiol.10091928] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
33
|
Shiomi T, Nishii T, Tanaka H, Yamazaki Y, Murase K, Myoui A, Yoshikawa H, Sugano N. Loading and knee alignment have significant influence on cartilage MRI T2 in porcine knee joints. Osteoarthritis Cartilage 2010; 18:902-8. [PMID: 20472084 DOI: 10.1016/j.joca.2010.05.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 04/27/2010] [Accepted: 05/03/2010] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Physiological magnetic resonance imaging (MRI) under loading or knee malalignment conditions has not been thoroughly investigated. We assessed the influence of static loading and knee alignment on T2 (transverse relaxation time) mapping of the knee femoral cartilage of porcine knee joints using a non-metallic pressure device. METHODS Ten porcine knee joints were harvested en bloc with intact capsules and surrounding muscles and imaged using a custom-made pressure device and 3.0-T MRI system. Sagittal T2 maps were obtained (1) at knee neutral alignment without external loading (no loading), (2) under mechanical compression of 140 N (neutral loading), and (3) under the same loading conditions as in (2) with the knee at 10 degrees varus alignment (varus loading). T2 values of deep, intermediate, and superficial zones of the medial and lateral femoral cartilages at the weight-bearing area were compared among these conditions using custom-made software. Cartilage contact pressure between the femoral and tibial cartilages, measured by a pressure-sensitive film, was correlated with cartilage T2 measurements. RESULTS In the medial cartilage, mean T2 values of the deep, intermediate, and superficial zones decreased by 1.4%, 13.0%, and 6.0% under neutral loading. They further decreased by 4.3%, 19.3%, and 17.2% under varus loading compared to no loading. In the lateral cartilage, these mean T2 values decreased by 3.9%, 7.7%, and 4.2% under neutral loading, but increased by 1.6%, 9.6%, and 7.2% under varus loading. There was a significant decrease in T2 values in the intermediate zone of the medial cartilage under both neutral and varus loading, and in the superficial zone of the medial cartilage under varus loading (P<0.05). Total contact pressure values under neutral loading and varus loading conditions significantly correlated with T2 values in the superficial and intermediate zones of the medial cartilages. CONCLUSIONS The response of T2 to change in static loading or alignment varied between the medial and lateral cartilages, and among the deep, intermediate, and superficial zones. These T2 changes were significantly related to the contact pressure measurements. Our results indicate that T2 mapping under loading allows non-invasive, biomechanical assessment of site-specific stress distribution in the cartilage.
Collapse
Affiliation(s)
- T Shiomi
- Department of Orthopaedic Surgery, Osaka University Medical School, Suita, Osaka, Japan
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Mosher TJ, Liu Y, Torok CM. Functional cartilage MRI T2 mapping: evaluating the effect of age and training on knee cartilage response to running. Osteoarthritis Cartilage 2010; 18:358-64. [PMID: 19948266 PMCID: PMC2826588 DOI: 10.1016/j.joca.2009.11.011] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 10/22/2009] [Accepted: 11/18/2009] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To characterize effects of age and physical activity level on cartilage thickness and T2 response immediately after running. DESIGN Institutional review board approval was obtained and all subjects provided informed consent prior to study participation. Cartilage thickness and magnetic resonance imaging (MRI) T2 values of 22 marathon runners and 15 sedentary controls were compared before and after 30 min of running. Runner and control groups were stratified by age<or=45 and >or=46 years. Multi-echo [(Time to Repetition (TR)/Time to Echo (TE) 1500 ms/9-109 ms)] MR images obtained using a 3.0 T scanner were used to calculate thickness and T2 values from the central femoral and tibial cartilage. Baseline cartilage T2 values, and change in cartilage thickness and T2 values after running were compared between the four groups using one-way analysis of variance (ANOVA). RESULTS After running MRI T2 values decreased in superficial femoral (2 ms-4 ms) and tibial (1 ms-3 ms) cartilage along with a decrease in cartilage thickness: (femoral: 4%-8%, tibial: 0%-12%). Smaller decrease in cartilage T2 values were observed in the middle zone of cartilage, and no change was observed in the deepest layer. There was no difference cartilage deformation or T2 response to running as a function of age or level of physical activity. CONCLUSIONS Running results in a measurable decrease in cartilage thickness and MRI T2 values of superficial cartilage consistent with greater compressibility of the superficial cartilage layer. Age and level of physical activity did not alter the T2 response to running.
Collapse
Affiliation(s)
- Timothy J. Mosher
- Penn State Center for NMR Research, Department of Radiology, The Penn State Milton S. Hershey Medical Center, Hershey, PA, USA 17033
| | - Yi Liu
- Department of Medicine, Roseville Sacramento Medical Center, 1001 Riverside Avenue, Roseville CA 95678
| | - Collin M. Torok
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, Maryland 21287
| |
Collapse
|
35
|
Anisotropic dynamic changes in the pore network structure, fluid diffusion and fluid flow in articular cartilage under compression. Biomaterials 2010; 31:3117-28. [PMID: 20144846 DOI: 10.1016/j.biomaterials.2010.01.102] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 01/15/2010] [Indexed: 10/19/2022]
Abstract
A compression cell designed to fit inside an NMR spectrometer was used to investigate the in situ mechanical strain response, structural changes to the internal pore structure, and the diffusion and flow of interstitial water in full-thickness cartilage samples as it was deforming dynamically under a constant compressive load (pressure). We distinguish between the hydrostatic pressure acting on the interstitial fluid and the pore pressure acting on the cartilage fibril network. Our results show that properties related to the pore matrix microstructure such as diffusion and hydraulic conductivity are strongly influenced by the hydrostatic pressure in the interstitial fluid of the dynamically deforming cartilage which differ significantly from the properties measured under static i.e. equilibrium loading conditions (when the hydrostatic pressure has relaxed back to zero). The magnitude of the hydrostatic fluid pressure also appears to affect the way cartilage's pore matrix changes during deformation with implications for the diffusion and flow-driven fluid transport through the deforming pore matrix. We also show strong evidence for a highly anisotropic pore structure and deformational dynamics that allows cartilage to deform without significantly altering the axial porosity of the matrix even at very large strains. The insensitivity of the axial porosity to compressive strain may be playing a critical function in directing the flow of pressurized interstitial fluid in the compressed cartilage to the surface, to support the load, and provide a protective interfacial fluid film that 'weeps' out from the deforming tissue and thereby enhances the (elasto)hydrodynamic efficacy of sliding joints. Our results appear to show a close synergy between the structure of cartilage and both the hydrodynamic and boundary lubrication mechanisms.
Collapse
|
36
|
Brama PAJ, Holopainen J, van Weeren PR, Firth EC, Helminen HJ, Hyttinen MM. Effect of loading on the organization of the collagen fibril network in juvenile equine articular cartilage. J Orthop Res 2009; 27:1226-34. [PMID: 19242977 DOI: 10.1002/jor.20866] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We investigated the effects of exercise-induced loading on the collagen network of equine articular cartilage. Collagen fibril architecture at a site (1) subjected to intermittent high-intensity loading was compared with that of an adjacent site (2) sustaining continuous low-level load. From horses exposed to forced exercise (CONDEX group) or not (PASTEX group), the spatial parallelism of fibrils and the orientation angle between fibrils and the surface at depths 9 microm apart through cartilage from surface to tidemark were determined using polarized light microscopy, and expressed as parallelism index (PI) and orientation index (OI). PI was significantly higher in site 2 than 1 in CONDEX and PASTEX groups. PI was significantly higher in forced exercised horses at site 2 but not site 1. OI was significantly greater (more perpendicular to the surface) in the superficial and deep cartilage of site 2 than 1 in both CONDEX and PASTEX groups. Superficial zone OI was higher in exercised horses at site 1 but not at site 2. Exercise increased collagen parallelism and affected orientation. The site differences in OI indicate that Benninghoff's classic predominantly perpendicular arcades appear not to be a consistent architectural feature, but adapt to local forces sustained.
Collapse
Affiliation(s)
- Pieter A J Brama
- School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
| | | | | | | | | | | |
Collapse
|
37
|
Mayerhoefer ME, Welsch GH, Mamisch TC, Kainberger F, Weber M, Nemec S, Friedrich KM, Dirisamer A, Trattnig S. The in vivo effects of unloading and compression on T1-Gd (dGEMRIC) relaxation times in healthy articular knee cartilage at 3.0 Tesla. Eur Radiol 2009; 20:443-9. [PMID: 19727756 DOI: 10.1007/s00330-009-1559-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 07/01/2009] [Accepted: 07/16/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE The purpose was to investigate the in vivo effects of unloading and compression on T1-Gd relaxation times in healthy articular knee cartilage. MATERIALS AND METHODS Ten volunteers were enrolled, and dGEMRIC images of their right knee joints were obtained using 3.0-T MR at three timepoints: directly following exercise ("baseline"), approximately 15 min after unloading ("unloading") and during application of a compressive force (50% of the body weight) generated by a loading device via a footplate ("compression"). RESULTS Our analysis of variance of pooled data from all cartilage zones demonstrated a significant mean T1-Gd decrease of 56.6 ms between baseline and compression (p < 0.001), and a significant mean decrease of 42.1 ms between unloading and compression (p < 0.001). No significant difference was found between baseline and unloading. Higher mean T1-Gd values were observed in the cartilage contact zone (central femoral and tibial zones; 698.3 +/- 162.2 ms) than in the non-contact zone (anterior and posterior femoral and tibial zones, and dorsal femoral zone; 662.9 +/- 149.3 ms; p < 0.01). CONCLUSION T1-Gd times appear to be sensitive to mechanical cartilage stress, and thus, further studies are warranted that investigate the relationship between the biochemical load response and the biomechanical properties of articular cartilage.
Collapse
Affiliation(s)
- Marius E Mayerhoefer
- Department of Radiology, MR Center, Medical University of Vienna, Lazarettgasse 14, 1090 Vienna, Austria
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Nishii T, Kuroda K, Matsuoka Y, Sahara T, Yoshikawa H. Change in knee cartilage T2 in response to mechanical loading. J Magn Reson Imaging 2008; 28:175-80. [PMID: 18581338 DOI: 10.1002/jmri.21418] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Takashi Nishii
- Department of Orthopaedic Surgery, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka, Japan.
| | | | | | | | | |
Collapse
|
39
|
Julkunen P, Korhonen RK, Nissi MJ, Jurvelin JS. Mechanical characterization of articular cartilage by combining magnetic resonance imaging and finite-element analysis—a potential functional imaging technique. Phys Med Biol 2008; 53:2425-38. [DOI: 10.1088/0031-9155/53/9/014] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
40
|
Xia Y. Averaged and depth-dependent anisotropy of articular cartilage by microscopic imaging. Semin Arthritis Rheum 2007; 37:317-27. [PMID: 17888496 DOI: 10.1016/j.semarthrit.2007.07.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 06/12/2007] [Accepted: 07/17/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVES To identify the common connections among the averaged and depth-dependent anisotropic properties of articular cartilage by performing a meta-analysis of several published multidisciplinary imaging results. The imaging techniques involved include microscopic magnetic resonance imaging (microMRI), polarized light microscopy (PLM), Fourier-transform infrared imaging (FTIRI), and transmission electron microscopy (TEM). METHODS Several physical properties of cartilage are incorporated in this meta-analysis. These tissue properties include T(2) anisotropy from microMRI, angle and retardance from PLM, infrared anisotropy from FTIRI, and image morphology from TEM. Because the specimens in these studies all came from the same type of canine humeral joints, it is possible to correlate these multidisciplinary tissue properties using a common platform. RESULTS An ellipse model was used to identify the connections among these tissue properties in terms of the anisotropy of articular cartilage, in each histological zone as well as for the entire noncalcified tissue. It was found that many aspects of these tissue properties can be interpreted beyond their usual meanings as measured, based on 3 features of an ellipse: the concentration, the orientation, and the anisotropy. CONCLUSIONS The ellipse model is a useful graphical concept in cartilage imaging since it helps to bring together the measured physical/morphological/chemical quantities in these imaging tools and the anisotropic structure of articular cartilage. Two possible mechanisms for the angular transition of collagen fibrils in cartilage are discussed.
Collapse
Affiliation(s)
- Yang Xia
- Department of Physics and Center for Biomedical Research, Oakland University, Rochester, Michigan 48309, USA.
| |
Collapse
|
41
|
Zernia G, Huster D. Collagen dynamics in articular cartilage under osmotic pressure. NMR IN BIOMEDICINE 2006; 19:1010-9. [PMID: 16823903 DOI: 10.1002/nbm.1061] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Cartilage is a complex biological tissue consisting of collagen, proteoglycans and water. The structure and molecular mobility of the collagen component of cartilage were studied by (13)C solid-state NMR spectroscopy as a function of hydration. The hydration level of cartilage was adjusted between fully hydrated ( approximately 80 wt% H(2)O) and highly dehydrated ( approximately 30 wt% H(2)O) using the osmotic stress technique. Thus, the conditions of mechanical load could be simulated and the response of the tissue macromolecules to mechanical stress is reported. From the NMR measurements, the following results were obtained. (i) Measurements of motionally averaged dipolar (1)H-(13)C couplings were carried out to study the segmental mobility in cartilage collagen at full hydration. Backbone segments undergo fast motions with amplitudes of approximately 35 degrees whereas the collagen side-chains are somewhat more mobile with amplitudes between 40 and 50 degrees . In spite of the high water content of cartilage, collagen remains essentially rigid. (ii) No chemical shift changes were observed in (13)C cross-polarization magic angle spinning spectra of cartilage tissue at varying hydration indicating that the collagen structure was not altered by application of high osmotic stress. (iii) The (1)H-(13)C dipolar coupling values detected for collagen signals respond to dehydration. The dipolar coupling values gradually increase upon cartilage dehydration, reaching rigid limit values at approximately 30 wt% H(2)O. This indicates that collagen is essentially dehydrated in cartilage tissue under very high mechanical load, which provides insights into the elastic properties of cartilage collagen, although the mechanical pressures applied here exceed the physiological limit.
Collapse
Affiliation(s)
- Göran Zernia
- Junior Research Group Solid-State NMR Studies of the Structure of Membrane-Associated Proteins, University of Leipzig, D-04107 Leipzig, Germany
| | | |
Collapse
|
42
|
Nissi MJ, Rieppo J, Töyräs J, Laasanen MS, Kiviranta I, Jurvelin JS, Nieminen MT. T(2) relaxation time mapping reveals age- and species-related diversity of collagen network architecture in articular cartilage. Osteoarthritis Cartilage 2006; 14:1265-71. [PMID: 16843689 DOI: 10.1016/j.joca.2006.06.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Accepted: 06/05/2006] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The magnetic resonance imaging (MRI) parameter T(2) relaxation time has been shown to be sensitive to the collagen network architecture of articular cartilage. The aim of the study was to investigate the agreement of T(2) relaxation time mapping and polarized light microscopy (PLM) for the determination of histological properties (i.e., zone and fibril organization) of articular cartilage. METHODS T(2) relaxation time was determined at 9.4 T field strength in healthy adult human, juvenile bovine and juvenile porcine patellar cartilage, and related to collagen anisotropy and fibril angle as measured by quantitative PLM. RESULTS Both T(2) and PLM revealed a mutually consistent but varying number of collagen-associated laminae (3, 3-5 or 3-7 laminae in human, porcine and bovine cartilage, respectively). Up to 44% of the depth-wise variation in T(2) was accounted for by the changing anisotropy of collagen fibrils, confirming that T(2) contrast of articular cartilage is strongly affected by the collagen fibril anisotropy. A good correspondence was observed between the thickness of T(2)-laminae and collagenous zones as determined from PLM anisotropy measurements (r=0.91, r=0.95 and r=0.91 for human, bovine and porcine specimens, respectively). CONCLUSIONS According to the present results, T(2) mapping is capable of detecting histological differences in cartilage collagen architecture among species, likely to be strongly related to the differences in maturation of the tissue. This diversity in the MRI appearance of healthy articular cartilage should also be recognized when using juvenile animal tissue as a model for mature human cartilage in experimental studies.
Collapse
Affiliation(s)
- M J Nissi
- Department of Physics, University of Kuopio, Kuopio, Finland.
| | | | | | | | | | | | | |
Collapse
|
43
|
Abstract
In T2-weighted MRI images joint cartilage can appear laminated. The multilaminar appearance is visualized as zones of different intensity. This appearance is based on the dipolar interaction of water molecules within cartilage zones of different collageneous network structures. Therefore, the MR visualization of zones of anisotropic arrangement of the collagen fibers depends upon their orientation to the static magnetic field (magic-angle effect). The aim of this article is to demonstrate the potential of high-resolution MRI for characterizing cartilage network structuring and biomechanical properties. Information equivalent to that from polarization light microscopy can be derived noninvasively. Based on NMR microscopic (microMRI) data, potential new possibilities of MRI for quantitative assessment of collagen structuring and intracartilagenous load distribution are presented. These methods use MR intensity angle dependence and load influence on cartilage visualization. Alternatively to the determination of mechanical parameters from cartilage deformation, it is demonstrated that stress distribution and biomechanical properties can be derived in principle from the local intensity variation of anisotropic fiber orientation zones. The limitations with respect to a clinical application of the proposed methods are discussed.
Collapse
Affiliation(s)
- Wilfried Gründer
- Institute of Medical Physics and Biophysics, University Leipzig, Härtelstrasse 16-18, D-04107 Leipzig, Germany.
| |
Collapse
|
44
|
Saar G, Shinar H, Navon G. Comparison of the effects of mechanical and osmotic pressures on the collagen fiber architecture of intact and proteoglycan-depleted articular cartilage. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2006; 36:529-38. [PMID: 17021804 DOI: 10.1007/s00249-006-0098-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 08/20/2006] [Accepted: 08/30/2006] [Indexed: 12/20/2022]
Abstract
One of the functions of articular cartilage is to withstand recurrent pressure applied in everyday life. In previous studies, osmotic pressure has been used to mimic the effects of mechanical pressure. In the present study, the response of the collagen network of intact and proteoglycans (PG)-depleted cartilage to mechanical and osmotic pressures is compared. The technique used is one-dimensional (2)H double quantum filtered spectroscopic MRI, which gives information about the degree of order and the density of the collagen fibers at the different locations throughout the intact tissue. For the nonpressurized plugs, the depletion had no effect on these parameters. Major differences were found in the zones near the bone between the effects of the two types of application of pressure for both intact and depleted plugs. While the order is lost in these zones as a result of mechanical load, it is preserved under osmotic pressure. For both intact and PG-depleted plugs under osmotic stress most of the collagen fibers become disordered. Our results indicate that different modes of strain are produced by unidirectional mechanical load and the isotropic osmotic stress. Thus, osmotic stress cannot serve as a model for the effect of load on cartilage in vivo.
Collapse
Affiliation(s)
- Galit Saar
- School of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel.
| | | | | |
Collapse
|
45
|
Kiviranta P, Rieppo J, Korhonen RK, Julkunen P, Töyräs J, Jurvelin JS. Collagen network primarily controls Poisson's ratio of bovine articular cartilage in compression. J Orthop Res 2006; 24:690-9. [PMID: 16514661 DOI: 10.1002/jor.20107] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The equilibrium Young's modulus of articular cartilage is known to be primarily determined by proteoglycans (PGs). However, the relation between the Poisson's ratio and the composition and structure of articular cartilage is more unclear. In this study, we determined Young's modulus and Poisson's ratio of bovine articular cartilage in unconfined compression. Subsequently, the same samples, taken from bovine knee (femoral, patellar and tibial cartilage) and shoulder (humeral cartilage) joints, were processed for quantitative microscopic analysis of PGs, collagen content, and collagen architecture. The Young's modulus, Poisson's ratio, PG content (estimated with optical density measurements), collagen content, and birefringence showed significant topographical variation (p < 0.05) among the test sites. Experimentally the Young's modulus was strongly determined by the tissue PG content (r = 0.86, p < 0.05). Poisson's ratio revealed a significant negative linear correlation (r = -0.59, p < 0.05) with the collagen content, as assessed by the Fourier transform infrared imaging. Finite element analyses, conducted using a fibril reinforced biphasic model, indicated that the mechanical properties of the collagen network strongly affected the Poisson's ratio. We conclude that Poisson's ratio of articular cartilage is primarily controlled by the content and organization of the collagen network.
Collapse
Affiliation(s)
- Panu Kiviranta
- Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital and University of Kuopio, Kuopio, Finland
| | | | | | | | | | | |
Collapse
|
46
|
Alhadlaq HA, Xia Y. Modifications of orientational dependence of microscopic magnetic resonance imaging T(2) anisotropy in compressed articular cartilage. J Magn Reson Imaging 2006; 22:665-73. [PMID: 16220547 DOI: 10.1002/jmri.20418] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To investigate the compression-induced changes in the orientational characteristics in T(2) anisotropy of articular cartilage using microscopic magnetic resonance imaging (microMRI). MATERIALS AND METHODS Six beagle specimens were subjected to various levels of strain (0% to 27%) and were imaged at a minimum of two orientations (0 degrees and 55 degrees ). Two specimens at 14% and 27% strain were imaged at every 5 degrees increment over the first quadrant of the angular space. Quantitative two-dimensional T(2) images and three-dimensional T(2) anisotropy maps of cartilage were constructed at a 19.8-microm in-depth resolution. RESULTS The load-induced laminar appearance of cartilage at the magic angle became more distinct as the strain level increased. T(2) anisotropy maps of cartilage at 14% and 27% strain exhibited load-induced modifications in the collagen fibril ultrastructure, with a new peak toward the cartilage-bone interface and alterations to orientational dependence of T(2) anisotropy. CONCLUSION Distinct alternations in the orientational dependence of microMRI T(2) anisotropy reflect the organizational modification of the collagen matrix due to external loading. This approach could become useful in detecting changes in cartilage's macromolecular structure due to injury or diseases.
Collapse
Affiliation(s)
- Hisham A Alhadlaq
- Department of Physics and Center for Biomedical Research, Oakland University, Rochester, Michigan 48309, USA
| | | |
Collapse
|
47
|
Périé D, Iatridis JC, Demers CN, Goswami T, Beaudoin G, Mwale F, Antoniou J. Assessment of compressive modulus, hydraulic permeability and matrix content of trypsin-treated nucleus pulposus using quantitative MRI. J Biomech 2006; 39:1392-400. [PMID: 15970200 DOI: 10.1016/j.jbiomech.2005.04.015] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Accepted: 04/13/2005] [Indexed: 11/21/2022]
Abstract
A clinical strength MRI and intact bovine caudal intervertebral discs were used to test the hypotheses that (1) mechanical loading and trypsin treatment induce changes in NMR parameters, mechanical properties and biochemical contents; and (2) mechanical properties are quantitatively related to NMR parameters. MRI acquisitions, confined compression stress-relaxation experiments, and biochemical assays were applied to determine the NMR parameters (relaxation times T1 and T2, magnetization transfer ratio (MTR) and diffusion trace (TrD)), mechanical properties (compressive modulus H(A0) and hydraulic permeability k(0)), and biochemical contents (H(2)O, proteoglycan and total collagen) of nucleus pulposus tissue from bovine caudal discs subjected to one of two injections and one of two mechanical loading conditions. Significant correlations were found between k(0) and T1 (r=0.75,p=0.03), T2 (r=0.78, p=0.02), and TrD (r=0.85, p=0.007). A trend was found between H(A0) and TrD (r=0.56, p=0.12). However, loading decreased these correlations (r=0.4, p=0.2). The significant effect of trypsin treatment on mechanical properties, but not on NMR parameters, may suggest that mechanical properties are more sensitive to the structural changes induced by trypsin treatment. The significant effect of loading on T1 and T2, but not on H(A0) or k(0), may suggest that NMR parameters are more sensitive to the changes in water content enhanced by loading. We conclude that MRI offers promise as a sensitive and non-invasive technique for describing alterations in material properties of intervertebral disc nucleus, and our results demonstrate that the hydraulic permeability correlated more strongly to the quantitative NMR parameters than did the compressive modulus; however, more studies are necessary to more precisely characterize these relationships.
Collapse
Affiliation(s)
- D Périé
- Department of mechanical engineering, University of Vermont, Burlington VT, USA.
| | | | | | | | | | | | | |
Collapse
|
48
|
Mosher TJ, Smith HE, Collins C, Liu Y, Hancy J, Dardzinski BJ, Smith MB. Change in Knee Cartilage T2 at MR Imaging after Running: A Feasibility Study. Radiology 2005; 234:245-9. [PMID: 15550376 DOI: 10.1148/radiol.2341040041] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
All participants provided informed consent to participate in this study, which was approved by the institutional review board of Milton S. Hershey Medical Center. The purpose of the study was to determine the feasibility of cartilage T2 mapping in the evaluation of response of femoral and tibial cartilage to running exercise. Quantitative magnetic resonance (MR) T2 maps of weight-bearing femoral and tibial articular cartilage were obtained in seven young healthy men before and immediately after 30 minutes of running by using a 3.0-T MR imager. There was no statistically significant change in T2 profiles of tibial cartilage. There was a statistically significant decrease in T2 of the superficial 40% of weight-bearing femoral cartilage after exercise. These in vivo observations agree well with published ex vivo results and support the hypothesis that cartilage compression results in greater anisotropy of superficial collagen fibers.
Collapse
Affiliation(s)
- Timothy J Mosher
- Pennsylvania State University Center for NMR Research, Department of Radiology, Milton S. Hershey Medical Center, 500 University Drive, Hershey, PA 17033, USA.
| | | | | | | | | | | | | |
Collapse
|
49
|
Seidel P, Hanke G, Gründer W. Load distribution of articular cartilage from MR-images by neural nets. Z Med Phys 2005; 15:101-6. [PMID: 16008079 DOI: 10.1078/0939-3889-00254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Artificial neural nets were used to determine the Young's modulus and spatial load distribution in articular cartilage by means of T2-weighted MR imaging. MR images were obtained in vitro (ex vivo?) from the joints of sheep of different ages (3 months, 9 months, 15 months, 1.5 years, 5 years, 5.5 years) and pigs (4 and 6 months) with a Bruker AMX 300 (7 T) spectrometer equipped with a micro-imaging unit. The knee of a 29-year-old male volunteer was studied in vivo under mechanical load using a clinical Siemens Vision MRT (1.5 T). The load of the cartilage is understood as a non-linear image transformation of loaded versus unloaded images. The artificial neural net was used to recognize given reference pixels of the unloaded cartilage within the image of the loaded cartilage. The Young's modulus was calculated from the local strain and the external pressure using the Hooke's law. With this method, the average Young's modulus was obtained in relationship to the biological age of the cartilage. The investigated age interval showed a progressive increase of 0.5 +/- 0.3 MPa per year. These results are consistent with published results. As shown in this pilot study, the method of neural nets allows the visualization of the spatial load distribution within the articular cartilage.
Collapse
Affiliation(s)
- Peter Seidel
- Institut der Medizinischen Physik und Biophysik der Universität Leipzig, Germany.
| | | | | |
Collapse
|
50
|
Keinan-Adamsky K, Shinar H, Navon G. The effect of detachment of the articular cartilage from its calcified zone on the cartilage microstructure, assessed by 2H-spectroscopic double quantum filtered MRI. J Orthop Res 2005; 23:109-17. [PMID: 15607882 DOI: 10.1016/j.orthres.2004.06.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2004] [Indexed: 02/04/2023]
Abstract
Most studies on articular cartilage properties have been conducted after detachment of the cartilage from the bone. In the present work we investigated the effect of detachment on collagen fiber architecture. We used one-dimensional (2)H double quantum filtered MRI on cartilage bone plugs equilibrated in deuterated saline. The quadrupolar splittings observed in the different zones were related to the degree of order and the density of the collagen fibers. The method is non-destructive, allowing for measurements on the same plug without the need for fixation, dehydration, sectioning and decalcification. Detachment of the radial from the calcified zone resulted in swelling of the cartilage plug in physiological saline and a concomitant decrease in the quadrupolar splitting. The effect of mechanical pressure on the (2)H quadrupolar splittings for the detached cartilage and for the calcified zone-bone plugs were compared with those of the same zones in the intact cartilage-bone plug. The splitting in the radial zone of the detached cartilage collapsed at much smaller loads compared to the intact cartilage-bone plug. The effect of the load on the size of the cartilage was also greater for the detached plug. These results indicate that anchoring of the cartilage to the bone through the calcified zone plays an important role in retaining the order of the collagen fibers. The water (2)H quadrupolar splitting in intact and proteoglycan-depleted cartilage was the same, indicating that the proteoglycans do not contribute to the ordering of the collagen fibers.
Collapse
|