The Experts below are selected from a list of 91443 Experts worldwide ranked by ideXlab platform

Stephen Rudin - One of the best experts on this subject based on the ideXlab platform.

  • tu fg 209 05 demonstration of the line Focus Principle using the generalized measured relative object detectability gm rod metric
    Medical Physics, 2016
    Co-Authors: M Russ, Daniel R Bednarek, Alok Shankar, A Lau, Stephen Rudin
    Abstract:

    Purpose: Demonstrate and quantify the augmented resolution due to focalspot size decrease in images acquired on the anode side of the field, for both small and medium (0.3 and 0.6mm) focal-spot sizes using the experimental task-based GM-ROD metric. Theoretical calculations have shown that a medium focal-spot can achieve the resolution of a small focal-spot if acquired with a tilted anode, effectively providing a higher-output small focal-spot. Methods: The MAF-CMOS (micro-angiographic fluoroscopic complementary-metal-oxide semiconductor) detector (75µm pixel pitch) imaged two copper wire segments of different diameter and a pipeline stent at the central axis and on the anode side of the beam, achieved by tilting the x-ray C-arm (Toshiba Infinix) to 6° and realigning the detector with the perpendicular ray to correct for x-ray obliquity. The relative gain in resolution was determined using the GM-ROD metric, which compares images on the basis of the Fourier transform of the image and the measured NNPS. To emphasize the geometric unsharpness, images were acquired at a magnification of two. Results: Images acquired on the anode side were compared to those acquired on the central axis with the same target-area focal-spot to consider the effect of an angled tube, and for all three objects the advantage of the smaller effective focal-spot was clear, showing a maximum improvement of 36% in GM-ROD. The images obtained with the small focal-spot at the central axis were compared to those of the medium focal-spot at the anode side and, for all objects, the relative performance was comparable. Conclusion: For three objects, the GM-ROD demonstrated the advantage of the anode side focal-spot. The comparable performance of the medium focal-spot on the anode side will allow for a high-output small focal-spot; a necessity in endovascular image-guided interventions. Partial support from an NIH grant R01EB002873 and an equipment grant from Toshiba Medical Systems Corp.

  • su gg i 174 use of line Focus Principle to increase the beam intensity while maintaining a high generalized mtf for the microangiographic fluoroscope maf system
    Medical Physics, 2010
    Co-Authors: Sandesh K Gupta, A Jain, Daniel R Bednarek, Stephen Rudin
    Abstract:

    Purpose: Achieving superior GMTF for the micro‐angiographic fluoroscope (MAF) system requires a small focal spot which could limit the range of possible beam intensities. We take advantage of the Line‐Focus Principle by using the medium focal spot viewed from the anode side rather than the small focal spot at the central axis to enable increased tube loading with no compromise in resolution. Method and Materials: We have calculated the GMTF at five different positions along the anode‐cathode direction parallel to the tube axis for the newly developed high resolution MAF (35 micron pixel). Focal spot measurements were done with a pin‐hole assembly using the same technique parameters at all positions. Small and medium focal spots and different object magnifications were used for GMTF comparisons. X‐ray intensity was determined at different positions parallel to the tube axis. Results: The comparison between the small focal spot at the center and the medium focal spot toward the anode direction demonstrated that there was only as small difference in resolution between these locations with only a 20% decrease in x‐ray intensity toward the anode side. Despite this decrease in x‐ray intensity due to the Heel effect, since the maximum tube loads were 500 and 160 mA for the two focal spots, respectively, the total increase in intensity for the medium focal spot can be a factor of 2.5 times that of the small focal spot. Focal spot blooming with the higher tube current for the medium focal spot was found to be negligible. Conclusions: This work demonstrates that by using the Line‐Focus Principle and a medium focal spot instead of a small focal spot at the center, a substantial increase in x‐ray output can be realized with minimal loss of total system spatial resolution or GMTF. (Support from: NIH Grants R01EB002873 and R01EB008425)

Xiaohua Zhu - One of the best experts on this subject based on the ideXlab platform.

  • Environmental behavior research in resources conservation and management: A case study of Resources, Conservation and Recycling
    Resources Conservation and Recycling, 2019
    Co-Authors: Fang Wang, Xiao Peng, Ran Wei, Yuelei Qin, Xiaohua Zhu
    Abstract:

    Abstract Considered as an approach to protect the environment and foster sustainability in severe environmental and ecosystem deterioration conditions, environmental behavior has received extensive, multidisciplinary research in recent decades. The general trend of environmental behavior research is profiled based on bibliometric analysis, which is set as the background of behavior research in the resources conservation and management field. Using materials from Resources, Conservation and Recycling (RCR) as well as its parent journals (RCRs), text mining is conducted to determine environmental behavior research scales, topics receiving Focus, Principle methods, and current research gaps. Future research and management practices are also suggested.

Daniel R Bednarek - One of the best experts on this subject based on the ideXlab platform.

  • tu fg 209 05 demonstration of the line Focus Principle using the generalized measured relative object detectability gm rod metric
    Medical Physics, 2016
    Co-Authors: M Russ, Daniel R Bednarek, Alok Shankar, A Lau, Stephen Rudin
    Abstract:

    Purpose: Demonstrate and quantify the augmented resolution due to focalspot size decrease in images acquired on the anode side of the field, for both small and medium (0.3 and 0.6mm) focal-spot sizes using the experimental task-based GM-ROD metric. Theoretical calculations have shown that a medium focal-spot can achieve the resolution of a small focal-spot if acquired with a tilted anode, effectively providing a higher-output small focal-spot. Methods: The MAF-CMOS (micro-angiographic fluoroscopic complementary-metal-oxide semiconductor) detector (75µm pixel pitch) imaged two copper wire segments of different diameter and a pipeline stent at the central axis and on the anode side of the beam, achieved by tilting the x-ray C-arm (Toshiba Infinix) to 6° and realigning the detector with the perpendicular ray to correct for x-ray obliquity. The relative gain in resolution was determined using the GM-ROD metric, which compares images on the basis of the Fourier transform of the image and the measured NNPS. To emphasize the geometric unsharpness, images were acquired at a magnification of two. Results: Images acquired on the anode side were compared to those acquired on the central axis with the same target-area focal-spot to consider the effect of an angled tube, and for all three objects the advantage of the smaller effective focal-spot was clear, showing a maximum improvement of 36% in GM-ROD. The images obtained with the small focal-spot at the central axis were compared to those of the medium focal-spot at the anode side and, for all objects, the relative performance was comparable. Conclusion: For three objects, the GM-ROD demonstrated the advantage of the anode side focal-spot. The comparable performance of the medium focal-spot on the anode side will allow for a high-output small focal-spot; a necessity in endovascular image-guided interventions. Partial support from an NIH grant R01EB002873 and an equipment grant from Toshiba Medical Systems Corp.

  • su gg i 174 use of line Focus Principle to increase the beam intensity while maintaining a high generalized mtf for the microangiographic fluoroscope maf system
    Medical Physics, 2010
    Co-Authors: Sandesh K Gupta, A Jain, Daniel R Bednarek, Stephen Rudin
    Abstract:

    Purpose: Achieving superior GMTF for the micro‐angiographic fluoroscope (MAF) system requires a small focal spot which could limit the range of possible beam intensities. We take advantage of the Line‐Focus Principle by using the medium focal spot viewed from the anode side rather than the small focal spot at the central axis to enable increased tube loading with no compromise in resolution. Method and Materials: We have calculated the GMTF at five different positions along the anode‐cathode direction parallel to the tube axis for the newly developed high resolution MAF (35 micron pixel). Focal spot measurements were done with a pin‐hole assembly using the same technique parameters at all positions. Small and medium focal spots and different object magnifications were used for GMTF comparisons. X‐ray intensity was determined at different positions parallel to the tube axis. Results: The comparison between the small focal spot at the center and the medium focal spot toward the anode direction demonstrated that there was only as small difference in resolution between these locations with only a 20% decrease in x‐ray intensity toward the anode side. Despite this decrease in x‐ray intensity due to the Heel effect, since the maximum tube loads were 500 and 160 mA for the two focal spots, respectively, the total increase in intensity for the medium focal spot can be a factor of 2.5 times that of the small focal spot. Focal spot blooming with the higher tube current for the medium focal spot was found to be negligible. Conclusions: This work demonstrates that by using the Line‐Focus Principle and a medium focal spot instead of a small focal spot at the center, a substantial increase in x‐ray output can be realized with minimal loss of total system spatial resolution or GMTF. (Support from: NIH Grants R01EB002873 and R01EB008425)

Fang Wang - One of the best experts on this subject based on the ideXlab platform.

  • Environmental behavior research in resources conservation and management: A case study of Resources, Conservation and Recycling
    Resources Conservation and Recycling, 2019
    Co-Authors: Fang Wang, Xiao Peng, Ran Wei, Yuelei Qin, Xiaohua Zhu
    Abstract:

    Abstract Considered as an approach to protect the environment and foster sustainability in severe environmental and ecosystem deterioration conditions, environmental behavior has received extensive, multidisciplinary research in recent decades. The general trend of environmental behavior research is profiled based on bibliometric analysis, which is set as the background of behavior research in the resources conservation and management field. Using materials from Resources, Conservation and Recycling (RCR) as well as its parent journals (RCRs), text mining is conducted to determine environmental behavior research scales, topics receiving Focus, Principle methods, and current research gaps. Future research and management practices are also suggested.

Ran Wei - One of the best experts on this subject based on the ideXlab platform.

  • Environmental behavior research in resources conservation and management: A case study of Resources, Conservation and Recycling
    Resources Conservation and Recycling, 2019
    Co-Authors: Fang Wang, Xiao Peng, Ran Wei, Yuelei Qin, Xiaohua Zhu
    Abstract:

    Abstract Considered as an approach to protect the environment and foster sustainability in severe environmental and ecosystem deterioration conditions, environmental behavior has received extensive, multidisciplinary research in recent decades. The general trend of environmental behavior research is profiled based on bibliometric analysis, which is set as the background of behavior research in the resources conservation and management field. Using materials from Resources, Conservation and Recycling (RCR) as well as its parent journals (RCRs), text mining is conducted to determine environmental behavior research scales, topics receiving Focus, Principle methods, and current research gaps. Future research and management practices are also suggested.