The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform
Jack C. Y. Cheng - One of the best experts on this subject based on the ideXlab platform.
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CT-based study of vertebral and intravertebral rotation in right thoracic adolescent idiopathic scoliosis
European Spine Journal, 2019Co-Authors: Rob C. Brink, Jelle F. Homans, Tom P. C. Schlösser, Marijn Stralen, Koen L. Vincken, Max A. Viergever, René M. Castelein, Jack C. Y. ChengAbstract:Purpose To define the longitudinal rotation axis around which individual vertebrae rotate, and to establish the various extra- and intravertebral rotation patterns in thoracic adolescent idiopathic scoliosis (AIS) patients, for better understanding of the 3D development of the rotational deformity. Methods Seventy high-resolution CT scans from an existing database of thoracic AIS patients (Cobb angle: 46°–109°) were included to determine the vertebral axial rotation, rotation radius, intravertebral axial rotation, and local Mechanical Torsion for each spinal level, using previously validated image processing techniques. Results For all levels, the longitudinal rotation axis, from which the vertebrae rotate away from the midline, was localized posterior to the spine. The axis became closer to the spine at the apex: apex, r = 11.5 ± 5.1 cm versus two levels above (radius = 15.8 ± 8.5 cm; p
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CT-based study of vertebral and intravertebral rotation in right thoracic adolescent idiopathic scoliosis
European Spine Journal, 2019Co-Authors: Rob C. Brink, Jelle F. Homans, Tom P. C. Schlösser, Marijn Stralen, Koen L. Vincken, Max A. Viergever, René M. Castelein, Jack C. Y. ChengAbstract:To define the longitudinal rotation axis around which individual vertebrae rotate, and to establish the various extra- and intravertebral rotation patterns in thoracic adolescent idiopathic scoliosis (AIS) patients, for better understanding of the 3D development of the rotational deformity. Seventy high-resolution CT scans from an existing database of thoracic AIS patients (Cobb angle: 46°–109°) were included to determine the vertebral axial rotation, rotation radius, intravertebral axial rotation, and local Mechanical Torsion for each spinal level, using previously validated image processing techniques. For all levels, the longitudinal rotation axis, from which the vertebrae rotate away from the midline, was localized posterior to the spine. The axis became closer to the spine at the apex: apex, r = 11.5 ± 5.1 cm versus two levels above (radius = 15.8 ± 8.5 cm; p
Brad Williamson - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the effect of vertebral and disc Mechanical Torsion on the correction achieved by posterior instrumentation in adolescent idiopathic scoliosis
Scoliosis, 2007Co-Authors: Daniel Birchall, David G. Hughes, Brad WilliamsonAbstract:Conclusion Mechanical Torsion within the vertebral bodies and discs of patients with idiopathic scoliosis presents a fundamental obstacle to effective derotational surgery, and is closely related to subsequent changes in the overall three-dimensional deformity following instrumentation. References 1. Benli IT, Akalin S, Aydin E, Baz A, Citak M, Kis M, Duman E: Isola spinal instrumentation system for IS. Arch Orthop and Trauma Surgery 2001, 121:17-25. from 4th International Conference on Conservative Management of Spinal Deformities Boston, MA, USA. 13–16 May 2007
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Demonstration of vertebral and disc Mechanical Torsion in adolescent idiopathic scoliosis using three-dimensional magnetic resonance imaging
Scoliosis, 2007Co-Authors: Daniel Birchall, David G. Hughes, Brad WilliamsonAbstract:Methods Ten patients with adolescent idiopathic scoliosis were imaged with three-dimensional MR imaging, and the data post-processed through multiplanar reconstruction to produce images angled through individual endplates. Transverse rotation was measured at each endplate and these measurements used to calculate the amount of vertebral and disc Mechanical Torsion present. A test object was imaged in order to validate the measurement technique.
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Demonstration of vertebral and disc Mechanical Torsion in adolescent idiopathic scoliosis using three-dimensional MR imaging
European Spine Journal, 2005Co-Authors: Daniel Birchall, David Hughes, Barbara Gregson, Brad WilliamsonAbstract:This study was designed to demonstrate and measure Mechanical Torsion in patients with adolescent idiopathic scoliosis using three-dimensional magnetic resonance (MR) imaging. Ten patients with adolescent idiopathic scoliosis were imaged with three-dimensional MR imaging, and the data post-processed through multiplanar reconstruction to produce images angled through individual endplates. Transverse rotation was measured at each endplate and these measurements used to calculate the amount of vertebral and disc Mechanical Torsion present. A test object was imaged in order to validate the measurement technique. Mechanical Torsion was demonstrated within the vertebral bodies and discs of the imaged subjects, with vertebral Mechanical Torsion contributing on average 45% of the overall transverse plane deformity. It is concluded that deformation occurs in the transverse plane within the vertebrae and discs of subjects with idiopathic scoliosis, and a significant proportion of the rotation present in the scoliotic spine occurs as a result of plastic deformation within the vertebrae themselves. We believe that this is the first systematic demonstration of Mechanical Torsion in idiopathic scoliosis.
Rob C. Brink - One of the best experts on this subject based on the ideXlab platform.
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CT-based study of vertebral and intravertebral rotation in right thoracic adolescent idiopathic scoliosis
European Spine Journal, 2019Co-Authors: Rob C. Brink, Jelle F. Homans, Tom P. C. Schlösser, Marijn Stralen, Koen L. Vincken, Max A. Viergever, René M. Castelein, Jack C. Y. ChengAbstract:Purpose To define the longitudinal rotation axis around which individual vertebrae rotate, and to establish the various extra- and intravertebral rotation patterns in thoracic adolescent idiopathic scoliosis (AIS) patients, for better understanding of the 3D development of the rotational deformity. Methods Seventy high-resolution CT scans from an existing database of thoracic AIS patients (Cobb angle: 46°–109°) were included to determine the vertebral axial rotation, rotation radius, intravertebral axial rotation, and local Mechanical Torsion for each spinal level, using previously validated image processing techniques. Results For all levels, the longitudinal rotation axis, from which the vertebrae rotate away from the midline, was localized posterior to the spine. The axis became closer to the spine at the apex: apex, r = 11.5 ± 5.1 cm versus two levels above (radius = 15.8 ± 8.5 cm; p
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CT-based study of vertebral and intravertebral rotation in right thoracic adolescent idiopathic scoliosis
European Spine Journal, 2019Co-Authors: Rob C. Brink, Jelle F. Homans, Tom P. C. Schlösser, Marijn Stralen, Koen L. Vincken, Max A. Viergever, René M. Castelein, Jack C. Y. ChengAbstract:To define the longitudinal rotation axis around which individual vertebrae rotate, and to establish the various extra- and intravertebral rotation patterns in thoracic adolescent idiopathic scoliosis (AIS) patients, for better understanding of the 3D development of the rotational deformity. Seventy high-resolution CT scans from an existing database of thoracic AIS patients (Cobb angle: 46°–109°) were included to determine the vertebral axial rotation, rotation radius, intravertebral axial rotation, and local Mechanical Torsion for each spinal level, using previously validated image processing techniques. For all levels, the longitudinal rotation axis, from which the vertebrae rotate away from the midline, was localized posterior to the spine. The axis became closer to the spine at the apex: apex, r = 11.5 ± 5.1 cm versus two levels above (radius = 15.8 ± 8.5 cm; p
Baiou Guan - One of the best experts on this subject based on the ideXlab platform.
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sampled bragg gratings formed in helically twisted fibers and their potential application for the simultaneous measurement of Mechanical Torsion and temperature
Optics Express, 2018Co-Authors: Jie Li, Gaoyang Chen, Chuang Wu, Baiou GuanAbstract:We propose and demonstrate a novel type of sampled Bragg gratings by combining a helically twisted fiber and a Bragg grating. A comb-like spectrum with a series of harmonic narrow resonances is observed, and the influence of geometrical parameters on the resonances is studied. As a special application, the intrinsic nature of the device that contains the Bragg grating and helical fiber spectral responses permits the temperature to be detected from the former, whereas the Mechanical Torsion is extracted from the latter, suggesting a potential for the simultaneous measurement of these two parameters. The proposed configuration features simplification, easy fabrication, high flexibility, stability, and low cost, and therefore has good prospects for sensor applications, as well as other applications, such as multi-channel filters, distributed Bragg reflectors, etc.
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few period helically twisted all solid photonic bandgap fibers
Optics Letters, 2018Co-Authors: Jie Li, Chuang Wu, Baiou GuanAbstract:We present a type of few-period helically twisted all-solid photonic bandgap fiber (AS-PBGFs). The helical structure leads to orbital resonance of a cladding rod light, which couples with the core mode. A two-period twist structure exhibits an extremely strong resonant dip of up to 30 dB. A series of samples with twist periods of 3.31–7.92 mm (yielding twist rates of 1.90−0.79 rad⋅mm−1) in association with different resonance orders are fabricated and demonstrated. The inherent physical mechanism underlying the resonance is analyzed. Moreover, the responses of the resonance to Mechanical Torsion, strain, and temperature are investigated. The twisted AS-PBGFs feature high reproducibility, stability, and robustness, and have great potential in tunable in-fiber filters and sensors.
Daniel Birchall - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the effect of vertebral and disc Mechanical Torsion on the correction achieved by posterior instrumentation in adolescent idiopathic scoliosis
Scoliosis, 2007Co-Authors: Daniel Birchall, David G. Hughes, Brad WilliamsonAbstract:Conclusion Mechanical Torsion within the vertebral bodies and discs of patients with idiopathic scoliosis presents a fundamental obstacle to effective derotational surgery, and is closely related to subsequent changes in the overall three-dimensional deformity following instrumentation. References 1. Benli IT, Akalin S, Aydin E, Baz A, Citak M, Kis M, Duman E: Isola spinal instrumentation system for IS. Arch Orthop and Trauma Surgery 2001, 121:17-25. from 4th International Conference on Conservative Management of Spinal Deformities Boston, MA, USA. 13–16 May 2007
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Demonstration of vertebral and disc Mechanical Torsion in adolescent idiopathic scoliosis using three-dimensional magnetic resonance imaging
Scoliosis, 2007Co-Authors: Daniel Birchall, David G. Hughes, Brad WilliamsonAbstract:Methods Ten patients with adolescent idiopathic scoliosis were imaged with three-dimensional MR imaging, and the data post-processed through multiplanar reconstruction to produce images angled through individual endplates. Transverse rotation was measured at each endplate and these measurements used to calculate the amount of vertebral and disc Mechanical Torsion present. A test object was imaged in order to validate the measurement technique.
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Demonstration of vertebral and disc Mechanical Torsion in adolescent idiopathic scoliosis using three-dimensional MR imaging
European Spine Journal, 2005Co-Authors: Daniel Birchall, David Hughes, Barbara Gregson, Brad WilliamsonAbstract:This study was designed to demonstrate and measure Mechanical Torsion in patients with adolescent idiopathic scoliosis using three-dimensional magnetic resonance (MR) imaging. Ten patients with adolescent idiopathic scoliosis were imaged with three-dimensional MR imaging, and the data post-processed through multiplanar reconstruction to produce images angled through individual endplates. Transverse rotation was measured at each endplate and these measurements used to calculate the amount of vertebral and disc Mechanical Torsion present. A test object was imaged in order to validate the measurement technique. Mechanical Torsion was demonstrated within the vertebral bodies and discs of the imaged subjects, with vertebral Mechanical Torsion contributing on average 45% of the overall transverse plane deformity. It is concluded that deformation occurs in the transverse plane within the vertebrae and discs of subjects with idiopathic scoliosis, and a significant proportion of the rotation present in the scoliotic spine occurs as a result of plastic deformation within the vertebrae themselves. We believe that this is the first systematic demonstration of Mechanical Torsion in idiopathic scoliosis.