This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the...This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the past 5 years.The photon energy range of the beamline is 8–72.5 keV.Several sets of X-ray imaging detectors with different pixel sizes(0.19–24 lm)are used to realize X-ray microcomputed tomography(X-ray micro-CT)and X-ray in-line phase-contrast imaging.To satisfy the requirements of user experiments,new X-ray imaging methods and image processing techniques are developed.In vivo dynamic micro-CT experiments with living insects are performed in 0.5 s(sampling rate of 2 Hz,2 tomograms/s)with a monochromatic beam from a wiggler source and in 40 ms(sampling rate of 25 Hz,25 tomograms/s)with a white beam from a bending magnet source.A new X-ray imaging method known as move contrast X-ray imaging is proposed,with which blood flow and moving tissues in raw images can be distinguished according to their moving frequencies in the time domain.Furthermore,X-ray speckle-tracking imaging with twice exposures to eliminate the edge enhancement effect is developed.A high-precision quantification method is realized to measure complex three-dimensional blood vessels obtained via X-ray micro-CT.X-ray imaging methods such as three-dimensional X-ray diffraction microscopy,small-angle X-ray scattering CT,and X-ray fluorescence CT are developed,in which the X-ray micro-CT imaging method is combined with other contrast mechanisms such as diffraction,scattering,and fluorescence contrasts respectively.Moreover,an X-ray nano-CT experiment is performed with a 100 nm spatial resolution.Typical user experimental results from the fields of material science,biomedicine,paleontology,physics,chemistry,and environmental science obtained on the beamline are provided.展开更多
Purpose: This study was undertaken to determine if portal-inflow bolus tracking outperforms aortic bolus tracking with respect to the image quality of contrast-enhanced portal venous-phase CT of the liver in patients ...Purpose: This study was undertaken to determine if portal-inflow bolus tracking outperforms aortic bolus tracking with respect to the image quality of contrast-enhanced portal venous-phase CT of the liver in patients without chronic liver damage. Materials and Methods: Contrast-enhanced CT of the liver was performed in 132 consecutive patients without chronic liver damage. Patients were prospectively assigned to three protocols: Protocol A—a portal venous-phase scan delay of 6 seconds after superior mesenteric venous (SMV) enhancement increased by 70 HU or 14 seconds after SMV enhancement was visually confirmed, and Protocols B and C—40 and 50 seconds, respectively, after abdominal aortic enhancement increased by 100 HU. Enhancement (ΔHU) of abdominal aorta, portal trunk, and liver parenchyma and diagnostic acceptability were assessed. Results: ΔHU of aorta was higher for protocol A than for protocols B and C (P P Conclusion: Portal-inflow bolus tracking did not outperform aortic tracking in terms of optimization of portal venous-phase CT in patients without chronic liver damage.展开更多
High-contrast is one of the main advantages in laser projection display, and the method of DCC (Dynamic Contrast Control) is the main way to increase the contrast. Generally, image pre-processing is necessary for elim...High-contrast is one of the main advantages in laser projection display, and the method of DCC (Dynamic Contrast Control) is the main way to increase the contrast. Generally, image pre-processing is necessary for eliminating noise and decreasing the over-highlight. In this paper, we proposed and actualized a method by following 3 steps: Firstly, the original image was analyzed statistically to get the scope of gray-scale distribution and average gray-scale;and then the image was divided into a number of sub-images. The sub-images whose pixels are higher than a certain threshold in both number and range, are applied image segmentation by certain growth rules. The sub-images satisfied with the growth rules are marked 1, and the rests are marked 0. Secondly, the sub-images are uniting. A sub-image has 3 relations between 8 sub-images around it: 1 and 1, 1 and 0, 0 and 0. The sub-images marked 1 are uniting together, and the sub-images marked 0 are uniting together. Without affecting the visual vision, all over-highlight pixels were reduced in a certain proportion. Lastly, based on the application of DCC, the whole image signals were enlarged and the brightness of light sources were reduced, so as to achieve the desired effect in contrast enhancement.展开更多
Therapies based on stem cell transplants offer significant potential in the field of regenerative medicine. Monitoring the fate of the transplanted stem cells in a timely manner is considered one of the main limitatio...Therapies based on stem cell transplants offer significant potential in the field of regenerative medicine. Monitoring the fate of the transplanted stem cells in a timely manner is considered one of the main limitations for long-standing success of stem cell transplants. Imaging methods that visualize and track stem cells<i> in vivo</i> non-invasively in real time are helpful towards the development of successful cell transplantation techniques. Novel molecular imaging methods which are non-invasive particularly such as MRI have been of great recent interest. Hence, mouse models which are of clinical relevance have been studied by injecting contrast agents used for labelling cells such as super-paramagnetic iron-oxide (SPIO) nanoparticles for cellular imaging. The MR techniques which can be used to generate positive contrast images have been of much relevance recently for tracking of the labelled cells. Particularly when the off-resonance region in the vicinity of the labeled cells is selectively excited while suppressing the signals from the non-labeled regions by the method of spectral dephasing. Thus, tracking of magnetically labelled cells employing positive contrast<i> in vivo</i> MR imaging methods in a burn mouse model in a non-invasive way has been the scope of this study. The consequences have direct implications for monitoring labeled stem cells at some stage in wound healing. We suggest that our approach can be used in clinical trials in molecular and regenerative medicine.展开更多
目的:探讨"双低"技术应用于主动脉CT血管造影(CT angiography,CTA)的可行性。方法:搜集70例体质量指数(body mass index,BMI)≤25 kg/m^2且临床拟行主动脉CTA病例,前瞻性随机分为常规组和实验组,每组35例,均以4 ml/s速率注入...目的:探讨"双低"技术应用于主动脉CT血管造影(CT angiography,CTA)的可行性。方法:搜集70例体质量指数(body mass index,BMI)≤25 kg/m^2且临床拟行主动脉CTA病例,前瞻性随机分为常规组和实验组,每组35例,均以4 ml/s速率注入碘海醇(350 mg I/ml)。常规组:120 k V、120 m As,对比剂用量1.5 ml/kg;实验组:90 k V、120 m As,对比剂用量1.0 ml/kg,其他扫描参数一致。记录并计算所有病例的辐射剂量、对比剂用量和碘含量,对图像质量进行双盲法主观评价和客观评价。结果:(1)实验组容积CT剂量指数(CT dose index volumes,CTDIvol)、剂量长度乘积(dose length product,DLP)、有效剂量(effect dose,ED)显著低于常规组(P<0.05)。(2)图像主观评分一致性较好(Kappa值>0.6),图像质量评分均≥2分,满足诊断要求,组间差异无统计学意义(P>0.05)。(3)客观评价实验组主动脉各部血管CT值、图像噪声显著高于常规组(P<0.05);2组间信噪比(signal noise ratio,SNR)、对比噪声比(contrast to noise ratio,CNR)差异无统计学意义(P>0.05)。实验组对比剂碘含量均明显低于常规组(P<0.05)。结论:在BMI≤25 kg/m^2的患者中行"双低"技术主动脉CTA,不仅有效降低了受检者辐射剂量和对比剂碘量,而且获得图像质量完全满足诊断要求,具有较好的临床应用价值。展开更多
基金This work was supported by the National Key Research and Development Program of China(Nos.2017YFA0403801,2016YFA0401302,2017YFA0206004,2018YFC1200204)the National Major Scientific Instruments and Equipment Development Project of China(No.11627901).
文摘This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the past 5 years.The photon energy range of the beamline is 8–72.5 keV.Several sets of X-ray imaging detectors with different pixel sizes(0.19–24 lm)are used to realize X-ray microcomputed tomography(X-ray micro-CT)and X-ray in-line phase-contrast imaging.To satisfy the requirements of user experiments,new X-ray imaging methods and image processing techniques are developed.In vivo dynamic micro-CT experiments with living insects are performed in 0.5 s(sampling rate of 2 Hz,2 tomograms/s)with a monochromatic beam from a wiggler source and in 40 ms(sampling rate of 25 Hz,25 tomograms/s)with a white beam from a bending magnet source.A new X-ray imaging method known as move contrast X-ray imaging is proposed,with which blood flow and moving tissues in raw images can be distinguished according to their moving frequencies in the time domain.Furthermore,X-ray speckle-tracking imaging with twice exposures to eliminate the edge enhancement effect is developed.A high-precision quantification method is realized to measure complex three-dimensional blood vessels obtained via X-ray micro-CT.X-ray imaging methods such as three-dimensional X-ray diffraction microscopy,small-angle X-ray scattering CT,and X-ray fluorescence CT are developed,in which the X-ray micro-CT imaging method is combined with other contrast mechanisms such as diffraction,scattering,and fluorescence contrasts respectively.Moreover,an X-ray nano-CT experiment is performed with a 100 nm spatial resolution.Typical user experimental results from the fields of material science,biomedicine,paleontology,physics,chemistry,and environmental science obtained on the beamline are provided.
文摘Purpose: This study was undertaken to determine if portal-inflow bolus tracking outperforms aortic bolus tracking with respect to the image quality of contrast-enhanced portal venous-phase CT of the liver in patients without chronic liver damage. Materials and Methods: Contrast-enhanced CT of the liver was performed in 132 consecutive patients without chronic liver damage. Patients were prospectively assigned to three protocols: Protocol A—a portal venous-phase scan delay of 6 seconds after superior mesenteric venous (SMV) enhancement increased by 70 HU or 14 seconds after SMV enhancement was visually confirmed, and Protocols B and C—40 and 50 seconds, respectively, after abdominal aortic enhancement increased by 100 HU. Enhancement (ΔHU) of abdominal aorta, portal trunk, and liver parenchyma and diagnostic acceptability were assessed. Results: ΔHU of aorta was higher for protocol A than for protocols B and C (P P Conclusion: Portal-inflow bolus tracking did not outperform aortic tracking in terms of optimization of portal venous-phase CT in patients without chronic liver damage.
文摘High-contrast is one of the main advantages in laser projection display, and the method of DCC (Dynamic Contrast Control) is the main way to increase the contrast. Generally, image pre-processing is necessary for eliminating noise and decreasing the over-highlight. In this paper, we proposed and actualized a method by following 3 steps: Firstly, the original image was analyzed statistically to get the scope of gray-scale distribution and average gray-scale;and then the image was divided into a number of sub-images. The sub-images whose pixels are higher than a certain threshold in both number and range, are applied image segmentation by certain growth rules. The sub-images satisfied with the growth rules are marked 1, and the rests are marked 0. Secondly, the sub-images are uniting. A sub-image has 3 relations between 8 sub-images around it: 1 and 1, 1 and 0, 0 and 0. The sub-images marked 1 are uniting together, and the sub-images marked 0 are uniting together. Without affecting the visual vision, all over-highlight pixels were reduced in a certain proportion. Lastly, based on the application of DCC, the whole image signals were enlarged and the brightness of light sources were reduced, so as to achieve the desired effect in contrast enhancement.
文摘Therapies based on stem cell transplants offer significant potential in the field of regenerative medicine. Monitoring the fate of the transplanted stem cells in a timely manner is considered one of the main limitations for long-standing success of stem cell transplants. Imaging methods that visualize and track stem cells<i> in vivo</i> non-invasively in real time are helpful towards the development of successful cell transplantation techniques. Novel molecular imaging methods which are non-invasive particularly such as MRI have been of great recent interest. Hence, mouse models which are of clinical relevance have been studied by injecting contrast agents used for labelling cells such as super-paramagnetic iron-oxide (SPIO) nanoparticles for cellular imaging. The MR techniques which can be used to generate positive contrast images have been of much relevance recently for tracking of the labelled cells. Particularly when the off-resonance region in the vicinity of the labeled cells is selectively excited while suppressing the signals from the non-labeled regions by the method of spectral dephasing. Thus, tracking of magnetically labelled cells employing positive contrast<i> in vivo</i> MR imaging methods in a burn mouse model in a non-invasive way has been the scope of this study. The consequences have direct implications for monitoring labeled stem cells at some stage in wound healing. We suggest that our approach can be used in clinical trials in molecular and regenerative medicine.
文摘目的:探讨"双低"技术应用于主动脉CT血管造影(CT angiography,CTA)的可行性。方法:搜集70例体质量指数(body mass index,BMI)≤25 kg/m^2且临床拟行主动脉CTA病例,前瞻性随机分为常规组和实验组,每组35例,均以4 ml/s速率注入碘海醇(350 mg I/ml)。常规组:120 k V、120 m As,对比剂用量1.5 ml/kg;实验组:90 k V、120 m As,对比剂用量1.0 ml/kg,其他扫描参数一致。记录并计算所有病例的辐射剂量、对比剂用量和碘含量,对图像质量进行双盲法主观评价和客观评价。结果:(1)实验组容积CT剂量指数(CT dose index volumes,CTDIvol)、剂量长度乘积(dose length product,DLP)、有效剂量(effect dose,ED)显著低于常规组(P<0.05)。(2)图像主观评分一致性较好(Kappa值>0.6),图像质量评分均≥2分,满足诊断要求,组间差异无统计学意义(P>0.05)。(3)客观评价实验组主动脉各部血管CT值、图像噪声显著高于常规组(P<0.05);2组间信噪比(signal noise ratio,SNR)、对比噪声比(contrast to noise ratio,CNR)差异无统计学意义(P>0.05)。实验组对比剂碘含量均明显低于常规组(P<0.05)。结论:在BMI≤25 kg/m^2的患者中行"双低"技术主动脉CTA,不仅有效降低了受检者辐射剂量和对比剂碘量,而且获得图像质量完全满足诊断要求,具有较好的临床应用价值。
