The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform
Jong Hyo Kim - One of the best experts on this subject based on the ideXlab platform.
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attenuation profile matching an accurate and Scan Parameter robust measurement method for small airway dimensions in low dose ct Scans
Medical Physics, 2018Co-Authors: Z Yang, Hyeongmin Jin, Jong Hyo KimAbstract:Purpose The dimensions of small airways with an internal diameter of less than 2-3 mm are important biomarkers for the evaluation of pulmonary diseases, such as asthma and chronic obstructive pulmonary disease (COPD). The resolution limitations of CT systems, however, have remained a barrier to be of use for determining the small airway dimensions. We present a novel approach, called the attenuation profile matching (APM) method, which allows for the accurate determination of the small airway dimension while being robust to varying CT Scan Parameters. Method For generating the synthetic attenuation profiles of an airway, we acquired and employed the point spread functions of a CT system by calculating its convolution with numerical airway models with varying wall thicknesses. The dimensions of a given airway were determined as per the numerical model yielding minimum error between the measured and the synthetic attenuation profiles across the airway. Results In a phantom study with airway tubes, the APM method proved to be highly accurate in determining airway wall dimensions. The measurement error for the smallest tube (0.6 mm thickness, 3 mm diameter) was merely 0.02 mm (3.3%) in wall thickness and 0.17 mm (5.6%) in lumen diameter. In a pilot clinical test, the APM method was able to distinguish the airway wall thicknesses of COPD cases (1.16 ± 0.23 mm) from those of normal subjects (0.6 ± 0.18 mm), while the measurements using the full width at half maximum method substantially overlapped (1.45 ± 0.32 mm vs. 1.28 ± 0.30 mm, respectively) and were barely distinguishable from each other. Conclusion Our proposed APM method has the potential to overcome the resolution limitations of current CT systems and accurately determine the small airway dimensions in COPD patients.
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Deep learning-enabled Scan Parameter normalization of imaging biomarkers in low-dose lung CT
2018 International Workshop on Advanced Image Technology (IWAIT), 2018Co-Authors: Hyeongmin Jin, Jong Hyo KimAbstract:CT Scan Parameters are known to strongly affect imaging biomarker quantification and increase variability of measurements. We present a deep learning-enabled recon kernel normalization technique and its effect in emphysema quantification in low-dose lung CT.
Hyeongmin Jin - One of the best experts on this subject based on the ideXlab platform.
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attenuation profile matching an accurate and Scan Parameter robust measurement method for small airway dimensions in low dose ct Scans
Medical Physics, 2018Co-Authors: Z Yang, Hyeongmin Jin, Jong Hyo KimAbstract:Purpose The dimensions of small airways with an internal diameter of less than 2-3 mm are important biomarkers for the evaluation of pulmonary diseases, such as asthma and chronic obstructive pulmonary disease (COPD). The resolution limitations of CT systems, however, have remained a barrier to be of use for determining the small airway dimensions. We present a novel approach, called the attenuation profile matching (APM) method, which allows for the accurate determination of the small airway dimension while being robust to varying CT Scan Parameters. Method For generating the synthetic attenuation profiles of an airway, we acquired and employed the point spread functions of a CT system by calculating its convolution with numerical airway models with varying wall thicknesses. The dimensions of a given airway were determined as per the numerical model yielding minimum error between the measured and the synthetic attenuation profiles across the airway. Results In a phantom study with airway tubes, the APM method proved to be highly accurate in determining airway wall dimensions. The measurement error for the smallest tube (0.6 mm thickness, 3 mm diameter) was merely 0.02 mm (3.3%) in wall thickness and 0.17 mm (5.6%) in lumen diameter. In a pilot clinical test, the APM method was able to distinguish the airway wall thicknesses of COPD cases (1.16 ± 0.23 mm) from those of normal subjects (0.6 ± 0.18 mm), while the measurements using the full width at half maximum method substantially overlapped (1.45 ± 0.32 mm vs. 1.28 ± 0.30 mm, respectively) and were barely distinguishable from each other. Conclusion Our proposed APM method has the potential to overcome the resolution limitations of current CT systems and accurately determine the small airway dimensions in COPD patients.
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Deep learning-enabled Scan Parameter normalization of imaging biomarkers in low-dose lung CT
2018 International Workshop on Advanced Image Technology (IWAIT), 2018Co-Authors: Hyeongmin Jin, Jong Hyo KimAbstract:CT Scan Parameters are known to strongly affect imaging biomarker quantification and increase variability of measurements. We present a deep learning-enabled recon kernel normalization technique and its effect in emphysema quantification in low-dose lung CT.
Yoshio Hiraki - One of the best experts on this subject based on the ideXlab platform.
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report on the 89th scientific assembly and annual meeting of the radiological society of north america analysis of radiation dose by a change of a Scan Parameter of multi slice computed tomography by a film method
Japanese Journal of Radiological Technology, 2004Co-Authors: Noriaki Akagi, Yoshihiro Ohkawa, Shigefumi Kadohisa, Yoshitada Nakagiri, Yoshio HirakiAbstract:PURPOSE It is for a purpose of this study to measure radiation dose by analyzing a dose profile of multi-slice computed tomography varying with helical pitch and a row slice thickness difference complicatedly. MATERIALS AND METHODS We used multi-slice computed tomography, and helical pitch and row slice thickness change and Scanned the helical Scan. I used CTDI phantom of a diameter of 25 cm and I inserted roentgen diagnosis use film UR-2(new) which I put between my own phantom in center and 1 cm away from the outer surface and Scanned it. And the provided level profile was converted into a dose profile with the dose-density curve which I made beforehand. I analyzed radiation dose than the dose profile. RESULT In multi-slice computed tomography, radiation dose varied with assembly of row slice thickness and helical pitch. The change of a dose profile changed in a phantom surface part complicatedly. The maximum dose by the measurement of this time was 29 mGy in row slice thickness 0.5 mm, assembly of helical pitch 2.5. In addition, the minimum dose was 6.8 mGy in row slice thickness 3.0 mm, assembly of helical pitch 5.5. And, as for the difference of maximum dose in the same dose profile and the smallest dose, there were about 20 % in row slice thickness 1.0 mm, assembly of helical pitch 5.5. CONCLUSION The dosimetry of multi-slice computed tomography by a film method enabled it to measure a change of a dose profile by a difference of a Scan Parameter by high interest solution ability. In addition, it is a method more superior in dosimetry of multi-slice computed tomography spreading through a Z-axis direction broadly than determination by computed tomography use ionization chamber dosimeter. Because radiation dose increases by a Scan in thin row slice thickness and small helical pitch, care is necessary.
Tony Lahoutte - One of the best experts on this subject based on the ideXlab platform.
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Quality control of micro-computed tomography systems
Radiation Protection Dosimetry, 2010Co-Authors: Liesbeth Eloot, N. Buls, P. Covens, Inneke Willekens, Tony LahoutteAbstract:: The rapid proliferation of micro-computed tomography (micro-CT) Scanners in preclinical small animal studies has created a need for a method on Scanner performance evaluation and Scan Parameter optimisation. The purpose of this study was to investigate the performance of the Scanner with a dedicated micro-CT phantom. The phantom was developed with different independent sections that allow for measurement of major Scanner characteristics such as uniformity, linearity, contrast response, dosimetry and resolution. The results of a thorough investigation are discussed.
Z Yang - One of the best experts on this subject based on the ideXlab platform.
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attenuation profile matching an accurate and Scan Parameter robust measurement method for small airway dimensions in low dose ct Scans
Medical Physics, 2018Co-Authors: Z Yang, Hyeongmin Jin, Jong Hyo KimAbstract:Purpose The dimensions of small airways with an internal diameter of less than 2-3 mm are important biomarkers for the evaluation of pulmonary diseases, such as asthma and chronic obstructive pulmonary disease (COPD). The resolution limitations of CT systems, however, have remained a barrier to be of use for determining the small airway dimensions. We present a novel approach, called the attenuation profile matching (APM) method, which allows for the accurate determination of the small airway dimension while being robust to varying CT Scan Parameters. Method For generating the synthetic attenuation profiles of an airway, we acquired and employed the point spread functions of a CT system by calculating its convolution with numerical airway models with varying wall thicknesses. The dimensions of a given airway were determined as per the numerical model yielding minimum error between the measured and the synthetic attenuation profiles across the airway. Results In a phantom study with airway tubes, the APM method proved to be highly accurate in determining airway wall dimensions. The measurement error for the smallest tube (0.6 mm thickness, 3 mm diameter) was merely 0.02 mm (3.3%) in wall thickness and 0.17 mm (5.6%) in lumen diameter. In a pilot clinical test, the APM method was able to distinguish the airway wall thicknesses of COPD cases (1.16 ± 0.23 mm) from those of normal subjects (0.6 ± 0.18 mm), while the measurements using the full width at half maximum method substantially overlapped (1.45 ± 0.32 mm vs. 1.28 ± 0.30 mm, respectively) and were barely distinguishable from each other. Conclusion Our proposed APM method has the potential to overcome the resolution limitations of current CT systems and accurately determine the small airway dimensions in COPD patients.
