The Experts below are selected from a list of 8361 Experts worldwide ranked by ideXlab platform
Anil T Ahuja - One of the best experts on this subject based on the ideXlab platform.
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shear wave Elastography of thyroid nodules in routine clinical practice preliminary observations and utility for detecting malignancy
European Radiology, 2012Co-Authors: Kunwar S S Bhatia, Yolanda Y P Lee, Carmen C M Cho, Cina S L Tong, Edmund H Y Yuen, Anil T AhujaAbstract:Objective To evaluate real-time shear wave Ultrasound Elastography (SWE) for characterizing focal thyroid lesions in routine clinical practice.
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cystic change in thyroid nodules a confounding factor for real time qualitative thyroid Ultrasound Elastography
Clinical Radiology, 2011Co-Authors: Kunwar S S Bhatia, D P Rasalkar, Yolanda Y P Lee, K T Wong, Ann D King, H Y Yuen, Anil T AhujaAbstract:Objective To evaluate real-time qualitative Ultrasound Elastography for focal thyroid masses undergoing fine-needle aspiration in a routine thyroid Ultrasound clinic. Materials and methods Ninety-four thyroid nodules scheduled for fine-needle aspiration cytology in a thyroid Ultrasound clinic also underwent real-time freehand Elastography. Colour-scaled elastograms were graded visually on the stiffness of the solid component of nodules relative to thyroid parenchyma using an Elastography score (ES) scale from 1 (soft) to 4 (stiff). The ES for benign and malignant nodules and the influence of cystic change on ES were analysed using Chi-square with trend and Fishers exact tests, with a p Results There were 19 papillary carcinomas, five metastases, 57 hyperplastic nodules, and four follicular adenomas based on definitive cytology ( n = 54) or histology ( n = 31). Nine nodules were excluded due to indeterminate cytology and no histology. Of malignancies (all solid), two were ES = 1, four were ES = 2, eight were ES = 3, and 10 were ES = 4. Of benign nodules, 17 were ES = 1, 17 were ES = 2, 16 were ES = 3, and 11 were ES = 4. An ES > 2 was more common in benign nodules with predominant cystic components (17/18) than mildly cystic (3/12) or completely solid (7/31) benign nodules ( p = 0.0004, p p = 0.09) unless partially cystic nodules were excluded ( p = 0.005). For solid nodules, an ES > 2 optimally predicted malignancy, achieving 74% sensitivity, 77% specificity, and 76% accuracy. Conclusion Qualitative real-time thyroid Elastography predicts malignancy only if predominantly cystic nodules are excluded, which may limit its utility in routine clinical practice.
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real time qualitative Ultrasound Elastography of cervical lymph nodes in routine clinical practice interobserver agreement and correlation with malignancy
Ultrasound in Medicine and Biology, 2010Co-Authors: Kunwar S S Bhatia, D P Rasalkar, Ann D King, Carmen C M Cho, Yuenhok Yuen, Anil T AhujaAbstract:To evaluate real-time qualitative Ultrasound (US) Elastography for cervical lymphadenopathy in routine clinical practice, 74 nodes (37 malignant, 37 benign) in 74 patients undergoing sonography underwent US Elastography prior to fine needle aspiration for cytology. Dynamic cine loops of elasticity imaging displayed using a chromatic-scale were qualitatively scored by three independent observers for the proportion of stiff areas from ES1-4 (soft to stiff). There was fair to good interobserver agreement as indicated by weighted kappa (κ) statistic from 0.374 to 0.738. Median ES for benign and malignant nodes were 2 and 3 respectively. ES was higher in malignant nodes (p = 0.0003-0.0049, Mann Whitney U tests) although areas under receiver operating characteristic curves (0.68-0.74) indicated suboptimal discrimination. The optimal discriminatory cut-off, ES > 2, achieved only 62.2% sensitivity, 83.8% specificity and 73% accuracy for malignancy. Improvements in reliability and accuracy of real-time qualitative Ultrasound Elastography are required for it to be adopted into routine clinical practice.
Kunwar S S Bhatia - One of the best experts on this subject based on the ideXlab platform.
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shear wave Elastography of thyroid nodules in routine clinical practice preliminary observations and utility for detecting malignancy
European Radiology, 2012Co-Authors: Kunwar S S Bhatia, Yolanda Y P Lee, Carmen C M Cho, Cina S L Tong, Edmund H Y Yuen, Anil T AhujaAbstract:Objective To evaluate real-time shear wave Ultrasound Elastography (SWE) for characterizing focal thyroid lesions in routine clinical practice.
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cystic change in thyroid nodules a confounding factor for real time qualitative thyroid Ultrasound Elastography
Clinical Radiology, 2011Co-Authors: Kunwar S S Bhatia, D P Rasalkar, Yolanda Y P Lee, K T Wong, Ann D King, H Y Yuen, Anil T AhujaAbstract:Objective To evaluate real-time qualitative Ultrasound Elastography for focal thyroid masses undergoing fine-needle aspiration in a routine thyroid Ultrasound clinic. Materials and methods Ninety-four thyroid nodules scheduled for fine-needle aspiration cytology in a thyroid Ultrasound clinic also underwent real-time freehand Elastography. Colour-scaled elastograms were graded visually on the stiffness of the solid component of nodules relative to thyroid parenchyma using an Elastography score (ES) scale from 1 (soft) to 4 (stiff). The ES for benign and malignant nodules and the influence of cystic change on ES were analysed using Chi-square with trend and Fishers exact tests, with a p Results There were 19 papillary carcinomas, five metastases, 57 hyperplastic nodules, and four follicular adenomas based on definitive cytology ( n = 54) or histology ( n = 31). Nine nodules were excluded due to indeterminate cytology and no histology. Of malignancies (all solid), two were ES = 1, four were ES = 2, eight were ES = 3, and 10 were ES = 4. Of benign nodules, 17 were ES = 1, 17 were ES = 2, 16 were ES = 3, and 11 were ES = 4. An ES > 2 was more common in benign nodules with predominant cystic components (17/18) than mildly cystic (3/12) or completely solid (7/31) benign nodules ( p = 0.0004, p p = 0.09) unless partially cystic nodules were excluded ( p = 0.005). For solid nodules, an ES > 2 optimally predicted malignancy, achieving 74% sensitivity, 77% specificity, and 76% accuracy. Conclusion Qualitative real-time thyroid Elastography predicts malignancy only if predominantly cystic nodules are excluded, which may limit its utility in routine clinical practice.
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real time qualitative Ultrasound Elastography of cervical lymph nodes in routine clinical practice interobserver agreement and correlation with malignancy
Ultrasound in Medicine and Biology, 2010Co-Authors: Kunwar S S Bhatia, D P Rasalkar, Ann D King, Carmen C M Cho, Yuenhok Yuen, Anil T AhujaAbstract:To evaluate real-time qualitative Ultrasound (US) Elastography for cervical lymphadenopathy in routine clinical practice, 74 nodes (37 malignant, 37 benign) in 74 patients undergoing sonography underwent US Elastography prior to fine needle aspiration for cytology. Dynamic cine loops of elasticity imaging displayed using a chromatic-scale were qualitatively scored by three independent observers for the proportion of stiff areas from ES1-4 (soft to stiff). There was fair to good interobserver agreement as indicated by weighted kappa (κ) statistic from 0.374 to 0.738. Median ES for benign and malignant nodes were 2 and 3 respectively. ES was higher in malignant nodes (p = 0.0003-0.0049, Mann Whitney U tests) although areas under receiver operating characteristic curves (0.68-0.74) indicated suboptimal discrimination. The optimal discriminatory cut-off, ES > 2, achieved only 62.2% sensitivity, 83.8% specificity and 73% accuracy for malignancy. Improvements in reliability and accuracy of real-time qualitative Ultrasound Elastography are required for it to be adopted into routine clinical practice.
Vappou Jonathan - One of the best experts on this subject based on the ideXlab platform.
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Investigation of PolyVinyl Chloride Plastisol Tissue-Mimicking Phantoms for MR- and Ultrasound-Elastography
'Frontiers Media SA', 2020Co-Authors: Chatelin S., Breton Elodie, Arulrajah Ajeethan, Giraudeau Céline, Wach Benoit, Meylheuc Laurence, Vappou JonathanAbstract:Objective: Realistic tissue-mimicking phantoms are essential for the development, the investigation and the calibration of medical imaging techniques and protocols. Because it requires taking both mechanical and imaging properties into account, the development of robust, calibrated phantoms is a major challenge in Elastography. Soft polyvinyl chloride gels in a liquid plasticizer (plastisol or PVCP) have been proposed as soft tissue-mimicking phantoms (TMP) for elasticity imaging. PVCP phantoms are relatively low-cost and can be easily stored over long time periods without any specific requirements. In this work, the preparation of a PVCP gel phantom for both MR and Ultrasound-Elastography is proposed and its acoustic, NMR and mechanical properties are studied.Materials and methods: The acoustic and magnetic resonance imaging properties of PVCP are measured for different mass ratios between Ultrasound speckle particles and PVCP solution, and between resin and plasticizer. The linear mechanical properties of plastisol samples are then investigated over time using not only indentation tests, but also MR and Ultrasound-Elastography clinical protocols. These properties are compared to typical values reported for biological soft tissues and to the values found in the literature for PVCP gels.Results and conclusions: After a period of two weeks, the mechanical properties of the plastisol samples measured with indentation testing are stable for at least the following 4 weeks (end of follow-up period 43 days after gelation-fusion). Neither the mechanical nor the NMR properties of plastisol gels were found to be affected by the addition of cellulose as acoustic speckle. Mechanical properties of the proposed gels were successfully characterized by clinical, commercially-available MR Elastography and sonoElastography protocols. PVCP with a mass ratio of Ultrasound speckle particles of 0.6%–0.8% and a mass ratio between resin and plasticizer between 50 and 70% appears as a good TMP candidate that can be used with both MR and Ultrasound-based Elastography methods
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Investigation of PVC plastisol tissue-mimicking phantoms for MR-and Ultrasound-Elastography
2020Co-Authors: Chatelin Simon, Breton Elodie, Arulrajah Ajeethan, Giraudeau Céline, Wach Benoit, Meylheuc Laurence, Vappou JonathanAbstract:Objective: Realistic tissue-mimicking phantoms are essential for the development, the investigation and the calibration of medical imaging techniques and protocols. Because it requires taking both mechanical and imaging properties into account, the development of robust, calibrated phantoms is a major challenge in Elastography. Soft polyvinyl chloride gels in a liquid plasticizer (plastisol or PVCP) have been proposed as soft tissue-mimicking phantoms (TMP) for elasticity imaging. PVCP phantoms are relatively low-cost and can be easily stored over long time periods without any specific requirements. In this work, the preparation of a PVCP gel phantom for both MR and UltrasoundElastography is proposed and its acoustic, NMR and mechanical properties are studied.Material and methods: The acoustic and magnetic resonance imaging properties of PVCP are measured for different mass ratios between Ultrasound speckle particles and PVCP solution, and between resin and plasticizer. The linear mechanical properties of plastisol samples are then investigated over time using not only indentation tests, but also MR and Ultrasound-Elastography clinical protocols. These properties are compared to typical values reported for biological soft tissues and to the values found in the literature for PVCP gels.Results and conclusions: After a period of two weeks, the mechanical properties of the plastisol samples measured with indentation testing are stable for at least the following 4 weeks (end of follow-up period 43 days after gelation-fusion). Neither the mechanical nor the NMR properties of plastisol gels were found to be affected by the addition of cellulose as acoustic speckle. Mechanical properties of the proposed gels were successfully characterized by clinical, commercially-available MR Elastography and sonoElastography protocols. PVCP with a mass ratio of Ultrasound speckle particles of 0.6% to 0.8% and a mass ratio between resin and plasticizer between 50 and 70% appears as a good TMP candidate that can be used with both MR and Ultrasound-based Elastography methods.Comment: Frontiers in Physics, Frontiers, In pres
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Investigation of PVC plastisol tissue-mimicking phantoms for MR-and Ultrasound-Elastography
'Frontiers in Bioscience', 2020Co-Authors: Chatelin Simon, Breton Elodie, Arulrajah Ajeethan, Giraudeau Céline, Wach Benoit, Meylheuc Laurence, Vappou JonathanAbstract:International audienceObjective: Realistic tissue-mimicking phantoms are essential for the development, the investigation and the calibration of medical imaging techniques and protocols. Because it requires taking both mechanical and imaging properties into account, the development of robust, calibrated phantoms is a major challenge in Elastography. Soft polyvinyl chloride gels in a liquid plasticizer (plastisol or PVCP) have been proposed as soft tissue-mimicking phantoms (TMP) for elasticity imaging. PVCP phantoms are relatively low-cost and can be easily stored over long time periods without any specific requirements. In this work, the preparation of a PVCP gel phantom for both MR and UltrasoundElastography is proposed and its acoustic, NMR and mechanical properties are studied.Material and methods: The acoustic and magnetic resonance imaging properties of PVCP are measured for different mass ratios between Ultrasound speckle particles and PVCP solution, and between resin and plasticizer. The linear mechanical properties of plastisol samples are then investigated over time using not only indentation tests, but also MR and Ultrasound-Elastography clinical protocols. These properties are compared to typical values reported for biological soft tissues and to the values found in the literature for PVCP gels.Results and conclusions: After a period of two weeks, the mechanical properties of the plastisol samples measured with indentation testing are stable for at least the following 4 weeks (end of follow-up period 43 days after gelation-fusion). Neither the mechanical nor the NMR properties of plastisol gels were found to be affected by the addition of cellulose as acoustic speckle. Mechanical properties of the proposed gels were successfully characterized by clinical, commercially-available MR Elastography and sonoElastography protocols. PVCP with a mass ratio of Ultrasound speckle particles of 0.6% to 0.8% and a mass ratio between resin and plasticizer between 50 and 70% appears as a good TMP candidate that can be used with both MR and Ultrasound-based Elastography methods
Carmen C M Cho - One of the best experts on this subject based on the ideXlab platform.
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shear wave Elastography of thyroid nodules in routine clinical practice preliminary observations and utility for detecting malignancy
European Radiology, 2012Co-Authors: Kunwar S S Bhatia, Yolanda Y P Lee, Carmen C M Cho, Cina S L Tong, Edmund H Y Yuen, Anil T AhujaAbstract:Objective To evaluate real-time shear wave Ultrasound Elastography (SWE) for characterizing focal thyroid lesions in routine clinical practice.
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real time qualitative Ultrasound Elastography of cervical lymph nodes in routine clinical practice interobserver agreement and correlation with malignancy
Ultrasound in Medicine and Biology, 2010Co-Authors: Kunwar S S Bhatia, D P Rasalkar, Ann D King, Carmen C M Cho, Yuenhok Yuen, Anil T AhujaAbstract:To evaluate real-time qualitative Ultrasound (US) Elastography for cervical lymphadenopathy in routine clinical practice, 74 nodes (37 malignant, 37 benign) in 74 patients undergoing sonography underwent US Elastography prior to fine needle aspiration for cytology. Dynamic cine loops of elasticity imaging displayed using a chromatic-scale were qualitatively scored by three independent observers for the proportion of stiff areas from ES1-4 (soft to stiff). There was fair to good interobserver agreement as indicated by weighted kappa (κ) statistic from 0.374 to 0.738. Median ES for benign and malignant nodes were 2 and 3 respectively. ES was higher in malignant nodes (p = 0.0003-0.0049, Mann Whitney U tests) although areas under receiver operating characteristic curves (0.68-0.74) indicated suboptimal discrimination. The optimal discriminatory cut-off, ES > 2, achieved only 62.2% sensitivity, 83.8% specificity and 73% accuracy for malignancy. Improvements in reliability and accuracy of real-time qualitative Ultrasound Elastography are required for it to be adopted into routine clinical practice.
Jonathan Vappou - One of the best experts on this subject based on the ideXlab platform.
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investigation of pvc plastisol tissue mimicking phantoms for mr and Ultrasound Elastography
arXiv: Medical Physics, 2020Co-Authors: Simon Chatelin, Elodie Breton, Ajeethan Arulrajah, Celine Giraudeau, Benoit Wach, Laurence Meylheuc, Jonathan VappouAbstract:Objective: Realistic tissue-mimicking phantoms are essential for the development, the investigation and the calibration of medical imaging techniques and protocols. Because it requires taking both mechanical and imaging properties into account, the development of robust, calibrated phantoms is a major challenge in Elastography. Soft polyvinyl chloride gels in a liquid plasticizer (plastisol or PVCP) have been proposed as soft tissue-mimicking phantoms (TMP) for elasticity imaging. PVCP phantoms are relatively low-cost and can be easily stored over long time periods without any specific requirements. In this work, the preparation of a PVCP gel phantom for both MR and UltrasoundElastography is proposed and its acoustic, NMR and mechanical properties are studied.Material and methods: The acoustic and magnetic resonance imaging properties of PVCP are measured for different mass ratios between Ultrasound speckle particles and PVCP solution, and between resin and plasticizer. The linear mechanical properties of plastisol samples are then investigated over time using not only indentation tests, but also MR and Ultrasound-Elastography clinical protocols. These properties are compared to typical values reported for biological soft tissues and to the values found in the literature for PVCP gels.Results and conclusions: After a period of two weeks, the mechanical properties of the plastisol samples measured with indentation testing are stable for at least the following 4 weeks (end of follow-up period 43 days after gelation-fusion). Neither the mechanical nor the NMR properties of plastisol gels were found to be affected by the addition of cellulose as acoustic speckle. Mechanical properties of the proposed gels were successfully characterized by clinical, commercially-available MR Elastography and sonoElastography protocols. PVCP with a mass ratio of Ultrasound speckle particles of 0.6% to 0.8% and a mass ratio between resin and plasticizer between 50 and 70% appears as a good TMP candidate that can be used with both MR and Ultrasound-based Elastography methods.
