The Experts below are selected from a list of 2070 Experts worldwide ranked by ideXlab platform
Kazuhisa Takahashi - One of the best experts on this subject based on the ideXlab platform.
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Corticosteroids and low bone mineral density affect hip Cartilage in systemic lupus erythematosus patients: Quantitative T2 mapping.
Journal of Magnetic Resonance Imaging, 2015Co-Authors: Shigeo Hagiwara, Atsuya Watanabe, Junichi Nakamura, Seiji Ohtori, Shunji Kishida, Takanori Omae, Shuichi Miyamoto, Sumihisa Orita, Kazuhisa TakahashiAbstract:Background The purpose of this diagnostic study was to quantify the effect of high-dose corticosteroid treatment on hip joint Cartilage degeneration in patients with systemic lupus erythematosus (SLE), with and without osteonecrosis, using magnetic resonance imaging (MRI). Methods T2 mapping, with a 3.0 Tesla Discovery MR750 (GE Healthcare) MRI scanner, was performed in 12 volunteers without hip pathology (control group, 12 hips), in 11 patients with SLE without osteonecrosis, who were receiving corticosteroid therapy (corticosteroid-ON group, 17 hips), and in 15 patients with SLE receiving corticosteroids, who had noncollapsed and asymptomatic osteonecrosis (corticosteroid+ON group, 26 hips). The distribution of T2 values in the Femoral Head and acetabular Cartilage were compared among the three groups. Step-wise multiple regression analysis was performed to determine the prognostic factors for T2 values indicative of Femoral Head Cartilage degeneration. Results Mean T2 values of Femoral Head Cartilage were significantly higher in the corticosteroid-ON (40.3 ms) and corticosteroid+ON (35.2 ms) groups than in the control group (30.1 ms, P = 0.001). T2 values of acetabular Cartilage were significantly higher in the corticosteroid-ON group (41.8 ms) versus the control (33.4 ms) and the corticosteroid+ON groups (37.0 ms; P = 0.001). Low bone mineral density was a significant prognostic factor for high T2 values of Cartilage at the Femoral Head in patients treated with corticosteroids, regardless of whether they had osteonecrosis. Conclusion T2 mapping suggests that corticosteroid therapy and osteoporosis are independent risk factors for Cartilage degeneration at the Femoral Head in patients with SLE. J. Magn. Reson. Imaging 2015
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Quantitative T2 mapping of Femoral Head Cartilage in systemic lupus erythematosus patients with noncollapsed osteonecrosis of the Femoral Head associated with corticosteroid therapy.
Journal of Magnetic Resonance Imaging, 2011Co-Authors: Shinji Yamamoto, Atsuya Watanabe, Junichi Nakamura, Seiji Ohtori, Yoshitada Harada, Shunji Kishida, Yuichi Wada, Kazuhisa TakahashiAbstract:Purpose: To evaluate articular Cartilage degeneration with transverse relaxation time (T2) mapping in systemic lupus erythematosus (SLE) patients with noncollapsed and asymptomatic osteonecrosis of the Femoral Head associated with corticosteroids. Materials and Methods: T2 mapping with a 1.5-T magnetic resonance imaging system was prospectively performed for 28 normal hips from 14 healthy volunteers (control group) and 15 hips from 10 SLE patients that met the inclusion criteria of noncollapsed and asymptomatic osteonecrosis of the Femoral Head (osteonecrosis group). Exclusion criteria were past experience of pain, trauma, infection, or prior hip joint surgery. Distribution of T2 values of the Femoral Head Cartilage were compared between the control group and the osteonecrosis group with respect to acetabular dysplasia by center-edge angle (CEA). Results: T2 values of the Femoral Head Cartilage were significantly higher in the osteonecrosis group than in the control group (34.4 msec vs. 30.8 msec, P = 0.001). Multiple regression analysis revealed that the osteonecrosis group and decreased CEA was significantly associated with high T2 values (T2 value = 34.6 + 3.6 × [osteonecrosis] − 0.14 × CEA, R2 = 0.52, P = 0.003). Conclusion: Degeneration of articular Cartilage was associated with osteonecrosis of the Femoral Head in SLE patients and acetabular dysplasia. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Johanne Martel-pelletier* - One of the best experts on this subject based on the ideXlab platform.
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Human Hip Joint Cartilage: MRI Quantitative Thickness and Volume Measurements Discriminating Acetabulum and Femoral Head
IEEE Transactions on Biomedical Engineering, 2008Co-Authors: Wei Li, FranÇois Abram, Gilles Beaudoin, Marie-josÉe Berthiaume, Jean-pierre Pelletier, Johanne Martel-pelletier*Abstract:This paper aims at developing a quantitative system for measuring human hip Cartilage thickness and volume using magnetic resonance imaging (MRI). A new MRI-acquisition technique, named axial rotation, where the acquisition planes are organized around a virtual axis, was used. The MRI protocol consists of a 2-D multiple-echo data image combination (MEDIC) using water excitation. Inner and outer interface contours of acetabulum and Femoral Head Cartilage are obtained using a semiautomated 3-D segmentation method and combined to form 3-D surfaces. A local spherical coordinate system computed from the original contours enables Cartilage thickness and volume computation. An anatomical labeling is performed automatically for thickness and volume measurements in predefined subregions: inferior, anterior, superior, and posterior. A registration module is introduced allowing the assessment of Cartilage changes over time. Validation of the system was conducted with three protocols each involving data obtained from nine subjects: 1) registration process accuracy; 2) intrareader reproducibility; and 3) intervisit coefficient of variation. Data showed excellent correlation coefficients for either the intrareader (r ges 0.0942, p < 0.0001) or intervisit (r ges 0.0837, p < 0.005) protocols. This noninvasive system, which enables the quantification of Cartilage thickness and volume in the human hip joint using MRI, is the first to discriminate the acetabular and Femoral Head Cartilage throughout the entire hip without the use of an external device, and to implement hip registration for follow-up studies on the same subject.
Jutta M. Ellermann - One of the best experts on this subject based on the ideXlab platform.
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Mapping IRM T2 pour une meilleure évaluation du Cartilage acétabulaire dans le conflit fémoro-acétabulaire : à propos d’un cas avec correlation arthroscopique
Revue de Chirurgie Orthopédique et Traumatologique, 2014Co-Authors: Patrick M. Morgan, Stanislav I. Spiridonov, Rainer Goebel, Mikko J. Nissi, R. Frei, Jutta M. EllermannAbstract:Abstract Articular Cartilage assessment in femoroacetabular impingement (FAI) is challenging. Recent studies on T2* relaxation time mapping suggest the technique may be useful in diagnosing Cartilage damage. The purpose of this case report is to describe how quantitative T2*-mapping may improve Cartilage assessment of the acetabulum in patients with FAI. MR arthrography was performed at 3 Tesla (T) using intra-articular Gadolinium and a T2* mapping protocol. Data from the acetabular Cartilage were separated from Femoral Head Cartilage data and then superimposed on a flattened, map-projection representation of the patient's acetabulum. The areas of unhealthy Cartilage observed at the time of arthroscopy – including debonding and delamination – were seen preoperatively at the same anatomic locations as areas of decreased T2* values. T2* mapping values provided a non-invasive assessment of the acetabular articular Cartilage. A flattened acetabular map projection allowed for anatomic visualization of areas of unhealthy Cartilage. Level of evidence Level IV.
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MR Imaging with T2*- mapping for improved acetabular Cartilage assessment in FAI-a case report with arthroscopic correlation
Orthopaedics & Traumatology: Surgery & Research, 2014Co-Authors: Patrick M. Morgan, Stanislav I. Spiridonov, Rainer Goebel, Mikko J. Nissi, R. Frei, Jutta M. EllermannAbstract:Abstract Articular Cartilage assessment in femoroacetabular impingement (FAI) is challenging. Recent studies on T2* relaxation time mapping suggest the technique may be useful in diagnosing Cartilage damage. The purpose of this case report is to describe how quantitative T2*-mapping may improve Cartilage assessment of the acetabulum in patients with FAI. MR arthrography was performed at 3 Tesla (T) using intra-articular Gadolinium and a T2* mapping protocol. Data from the acetabular Cartilage was separated from Femoral Head Cartilage data and then superimposed on a flattened, map projection representation of the patient's acetabulum. The areas of unhealthy Cartilage observed at the time of arthroscopy – including debonding and delamination – were seen preoperatively at the same anatomic locations as areas of decreased T2* values. T2* mapping values provided a non-invasive assessment of the acetabular articular Cartilage. A flattened acetabular map projection allowed for anatomic visualization of areas of unhealthy Cartilage. Level of evidence Level IV.
F. M. Desa - One of the best experts on this subject based on the ideXlab platform.
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The effects of estrogens on Cartilage degradation using in vivo and in vitro models.
Inflammation Research, 1991Co-Authors: C L Chander, F. M. DesaAbstract:We have investigated the effects of estradiol on Cartilage breakdown. The model of arthritis used involved the subcutaneous implantation of rat Femoral Head Cartilage (FHCs) into the dorsal region of female mice. The FHCs had been previously wrapped in sterile 5 mg cotton to provoke the growth of granulomatous tissue adjacent to Cartilage. Animals were dosed daily, a day after implantation, for 14 days with either 17β-estradiol or tamoxifen at different doses. The FHCs were removed and analysed for glycosaminoglycan (GAG) content. The results demonstrated that estradiol accelerated Cartilage breakdown in a dose dependent manner, an effect which is blocked by tamoxifen. In addition, estradiol was found to increase Cartilage degradation in anin vitro model using FHCs. This effect was enhanced by the addition of fibroblasts.
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The effects of estrogens on Cartilage degradation using in vivo and in vitro models.
Agents and Actions, 1991Co-Authors: C L Chander, F. M. DesaAbstract:We have investigated the effects of estradiol on Cartilage breakdown. The model of arthritis used involved the subcutaneous implantation of rat Femoral Head Cartilage (FHCs) into the dorsal region of female mice. The FHCs had been previously wrapped in sterile 5 mg cotton to provoke the growth of granulomatous tissue adjacent to Cartilage. Animals were dosed daily, a day after implantation, for 14 days with either 17 beta-estradiol or tamoxifen at different doses. The FHCs were removed and analysed for glycosaminoglycan (GAG) content. The results demonstrated that estradiol accelerated Cartilage breakdown in a dose dependent manner, an effect which is blocked by tamoxifen. In addition, estradiol was found to increase Cartilage degradation in an in vitro model using FHCs. This effect was enhanced by the addition of fibroblasts.
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The synergism between platelet-activating factor and interleukin-1 on Cartilage breakdown.
Journal of lipid mediators, 1990Co-Authors: D. W. Howat, F. M. Desa, C. Chander, A. Moore, D.a. WilloughbyAbstract:The breakdown of rat articular Cartilage has been studied in vivo and in vitro to observe the effect of platelet-activating factor (PAF) and interleukin-1 alpha (IL-1 alpha) on the net loss of glycosaminoglycan (GAG). When PAF was infused over a 2-week period into rats, there was no increased breakdown of implanted, cotton-wrapped, Femoral Head Cartilage. However, there was a loss of proteoglycan from the Femoral Head Cartilage of the recipient rats (native Cartilage). This loss from the native Cartilage was not apparent if the animal had not been implanted with Cartilage. Using an in vitro system, the effect of PAF and IL-1 alpha on rat Femoral Head Cartilage was further examined. Separately, neither agent had any significant effect on GAG content. However, when combined, there was a significant loss of GAG. The significance of these results is discussed.
Wei Li - One of the best experts on this subject based on the ideXlab platform.
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Human Hip Joint Cartilage: MRI Quantitative Thickness and Volume Measurements Discriminating Acetabulum and Femoral Head
IEEE Transactions on Biomedical Engineering, 2008Co-Authors: Wei Li, FranÇois Abram, Gilles Beaudoin, Marie-josÉe Berthiaume, Jean-pierre Pelletier, Johanne Martel-pelletier*Abstract:This paper aims at developing a quantitative system for measuring human hip Cartilage thickness and volume using magnetic resonance imaging (MRI). A new MRI-acquisition technique, named axial rotation, where the acquisition planes are organized around a virtual axis, was used. The MRI protocol consists of a 2-D multiple-echo data image combination (MEDIC) using water excitation. Inner and outer interface contours of acetabulum and Femoral Head Cartilage are obtained using a semiautomated 3-D segmentation method and combined to form 3-D surfaces. A local spherical coordinate system computed from the original contours enables Cartilage thickness and volume computation. An anatomical labeling is performed automatically for thickness and volume measurements in predefined subregions: inferior, anterior, superior, and posterior. A registration module is introduced allowing the assessment of Cartilage changes over time. Validation of the system was conducted with three protocols each involving data obtained from nine subjects: 1) registration process accuracy; 2) intrareader reproducibility; and 3) intervisit coefficient of variation. Data showed excellent correlation coefficients for either the intrareader (r ges 0.0942, p < 0.0001) or intervisit (r ges 0.0837, p < 0.005) protocols. This noninvasive system, which enables the quantification of Cartilage thickness and volume in the human hip joint using MRI, is the first to discriminate the acetabular and Femoral Head Cartilage throughout the entire hip without the use of an external device, and to implement hip registration for follow-up studies on the same subject.
