The Experts below are selected from a list of 189492 Experts worldwide ranked by ideXlab platform
Jun Chen - One of the best experts on this subject based on the ideXlab platform.
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fully vacuum sealed diode structure addressable zno nanowire cold cathode flat panel X Ray Source fabrication and imaging application
Nanomaterials, 2021Co-Authors: Chengyun Wang, Shao Zhi Deng, Guofu Zhang, Yicong Chen, Jun ChenAbstract:A fully vacuum-sealed addressable flat-panel X-Ray Source based on ZnO nanowire field emitter arRays (FEAs) was fabricated. The device has a diode structure composed of cathode panel and anode panel. ZnO nanowire cold cathodes were prepared on strip electrodes on a cathode panel and Mo thin film strips were prepared on an anode panel acting as the target. Localized X-Ray emission was realized by cross-addressing of cathode and anode electrodes. A radiation dose rate of 10.8 μGy/s was recorded at the anode voltage of 32 kV. The X-Ray imaging of objects using different addressing scheme was obtained and the imaging results were analyzed. The results demonstrated the feasibility of achieving addressable flat-panel X-Ray Source using diode-structure for advanced X-Ray imaging.
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fully vacuum sealed addressable nanowire cold cathode flat panel X Ray Source
Applied Physics Letters, 2021Co-Authors: Xiuqing Cao, Shao Zhi Deng, Juncong She, Guofu Zhang, Yangyang Zhao, Jun ChenAbstract:Addressable flat-panel X-Ray Source has important applications in neXt-generation low-dose X-Ray imaging technology. In this study, a fully vacuum-sealed addressable flat-panel X-Ray Source has been fabricated using a ZnO nanowire cold cathode. The X-Ray Source was formed by assembling gated ZnO nanowire field emitters and a molybdenum thin film transmission anode target. Pulsed and addressable X-Ray emission was achieved by applying voltages to the eXtraction gate. Radiation dose rates of 235 nGy/s were achieved when the device was operated at 21 kV anode voltage and 140 V gate voltage. Projection X-Ray images of objects were obtained by the flat-panel X-Ray Source. Our results demonstrated the feasibility of a fully addressable cold cathode flat-panel X-Ray Source.
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fabrication of zno nanowires cold cathode X Ray Source with micro patterned transmission anode
International Vacuum Nanoelectronics Conference, 2021Co-Authors: Song Kang, Shao Zhi Deng, Guofu Zhang, Yangyang Zhao, Jun ChenAbstract:Flat-panel X-Ray Source could realize compact imaging system with low dosage. In order to better control the size of X-Ray emission spot from the flat panel X-Ray Source, we fabricated a flat panel X-Ray Source with micro-pattern transmission anode. The size of X-Ray emission spot can be accurately controlled by modulating the size of the transmission anode pattern, which is eXpected to improve the imaging performance.
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optimization of focusing structure for a micro focus X Ray Source
International Vacuum Nanoelectronics Conference, 2021Co-Authors: Junfan Wang, Shao Zhi Deng, Yajie Guo, Haifeng Zhu, Yu Zhang, Jun ChenAbstract:Cold cathode micro-focus X-Ray Source with a single focusing lens was designed. The focus spot size (FSS) of the electron beam was simulated using CST software. The simulation method is verified by eXperimental results using an electron gun consisting of gated carbon nanotube cold cathode and focusing electrode.
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development of gated carbon nanotube cold cathode for miniature X Ray Source
International Vacuum Nanoelectronics Conference, 2021Co-Authors: Yajie Guo, Shao Zhi Deng, Junfan Wang, Yu Zhang, Jun ChenAbstract:A gated carbon nanotube cold cathode has been fabricated for miniature X-Ray Source application. Randomly aligned CNTs were prepared using CVD. Gated CNT cold cathode was fabricated using a metal mesh gate. The current-voltage characteristics, gate transmission rate and the current stability were studied. Current fluctuation less than 1% was achieved.
Shao Zhi Deng - One of the best experts on this subject based on the ideXlab platform.
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fully vacuum sealed diode structure addressable zno nanowire cold cathode flat panel X Ray Source fabrication and imaging application
Nanomaterials, 2021Co-Authors: Chengyun Wang, Shao Zhi Deng, Guofu Zhang, Yicong Chen, Jun ChenAbstract:A fully vacuum-sealed addressable flat-panel X-Ray Source based on ZnO nanowire field emitter arRays (FEAs) was fabricated. The device has a diode structure composed of cathode panel and anode panel. ZnO nanowire cold cathodes were prepared on strip electrodes on a cathode panel and Mo thin film strips were prepared on an anode panel acting as the target. Localized X-Ray emission was realized by cross-addressing of cathode and anode electrodes. A radiation dose rate of 10.8 μGy/s was recorded at the anode voltage of 32 kV. The X-Ray imaging of objects using different addressing scheme was obtained and the imaging results were analyzed. The results demonstrated the feasibility of achieving addressable flat-panel X-Ray Source using diode-structure for advanced X-Ray imaging.
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fully vacuum sealed addressable nanowire cold cathode flat panel X Ray Source
Applied Physics Letters, 2021Co-Authors: Xiuqing Cao, Shao Zhi Deng, Juncong She, Guofu Zhang, Yangyang Zhao, Jun ChenAbstract:Addressable flat-panel X-Ray Source has important applications in neXt-generation low-dose X-Ray imaging technology. In this study, a fully vacuum-sealed addressable flat-panel X-Ray Source has been fabricated using a ZnO nanowire cold cathode. The X-Ray Source was formed by assembling gated ZnO nanowire field emitters and a molybdenum thin film transmission anode target. Pulsed and addressable X-Ray emission was achieved by applying voltages to the eXtraction gate. Radiation dose rates of 235 nGy/s were achieved when the device was operated at 21 kV anode voltage and 140 V gate voltage. Projection X-Ray images of objects were obtained by the flat-panel X-Ray Source. Our results demonstrated the feasibility of a fully addressable cold cathode flat-panel X-Ray Source.
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fabrication of zno nanowires cold cathode X Ray Source with micro patterned transmission anode
International Vacuum Nanoelectronics Conference, 2021Co-Authors: Song Kang, Shao Zhi Deng, Guofu Zhang, Yangyang Zhao, Jun ChenAbstract:Flat-panel X-Ray Source could realize compact imaging system with low dosage. In order to better control the size of X-Ray emission spot from the flat panel X-Ray Source, we fabricated a flat panel X-Ray Source with micro-pattern transmission anode. The size of X-Ray emission spot can be accurately controlled by modulating the size of the transmission anode pattern, which is eXpected to improve the imaging performance.
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optimization of focusing structure for a micro focus X Ray Source
International Vacuum Nanoelectronics Conference, 2021Co-Authors: Junfan Wang, Shao Zhi Deng, Yajie Guo, Haifeng Zhu, Yu Zhang, Jun ChenAbstract:Cold cathode micro-focus X-Ray Source with a single focusing lens was designed. The focus spot size (FSS) of the electron beam was simulated using CST software. The simulation method is verified by eXperimental results using an electron gun consisting of gated carbon nanotube cold cathode and focusing electrode.
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development of gated carbon nanotube cold cathode for miniature X Ray Source
International Vacuum Nanoelectronics Conference, 2021Co-Authors: Yajie Guo, Shao Zhi Deng, Junfan Wang, Yu Zhang, Jun ChenAbstract:A gated carbon nanotube cold cathode has been fabricated for miniature X-Ray Source application. Randomly aligned CNTs were prepared using CVD. Gated CNT cold cathode was fabricated using a metal mesh gate. The current-voltage characteristics, gate transmission rate and the current stability were studied. Current fluctuation less than 1% was achieved.
Guang Yang - One of the best experts on this subject based on the ideXlab platform.
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High resolution stationary digital breast tomosynthesis using distributed carbon nanotube X-Ray Source arRay
Medical Physics, 2012Co-Authors: Xin Qian, Emily Gidcumb, Xiomara Calderon-colon, Shabana Sultana, Andrew Tucker, Jianping Lu, Guang Yang, Derrek SpronkAbstract:PURPOSE: The purpose of this study is to investigate the feasibility of increasing the system spatial resolution and scanning speed of Hologic Selenia Dimensions digital breast tomosynthesis (DBT) scanner by replacing the rotating mammography X-Ray tube with a specially designed carbon nanotube (CNT) X-Ray Source arRay, which generates all the projection images needed for tomosynthesis reconstruction by electronically activating individual X-Ray Sources without any mechanical motion. The stationary digital breast tomosynthesis (s-DBT) design aims to (i) increase the system spatial resolution by eliminating image blurring due to X-Ray tube motion and (ii) reduce the scanning time. Low spatial resolution and long scanning time are the two main technical limitations of current DBT technology.\n\nMETHODS: A CNT X-Ray Source arRay was designed and evaluated against a set of targeted system performance parameters. Simulations were performed to determine the maXimum anode heat load at the desired focal spot size and to design the electron focusing optics. Field emission current from CNT cathode was measured for an eXtended period of time to determine the stable life time of CNT cathode for an eXpected clinical operation scenario. The Source arRay was manufactured, tested, and integrated with a Selenia scanner. An electronic control unit was developed to interface the Source arRay with the detection system and to scan and regulate X-Ray beams. The performance of the s-DBT system was evaluated using physical phantoms.\n\nRESULTS: The spatially distributed CNT X-Ray Source arRay comprised 31 individually addressable X-Ray Sources covering a 30 angular span with 1 pitch and an isotropic focal spot size of 0.6 mm at full width at half-maXimum. Stable operation at 28 kV(peak) anode voltage and 38 mA tube current was demonstrated with eXtended lifetime and good Source-to-Source consistency. For the standard imaging protocol of 15 views over 14, 100 mAs dose, and 2 × 2 detector binning, the projection resolution along the scanning direction increased from 4.0 cycles/mm [at 10% modulation-transfer-function (MTF)] in DBT to 5.1 cycles/mm in s-DBT at magnification factor of 1.08. The improvement is more pronounced for faster scanning speeds, wider angular coverage, and smaller detector piXel sizes. The scanning speed depends on the detector, the number of views, and the imaging dose. With 240 ms detector readout time, the s-DBT system scanning time is 6.3 s for a 15-view, 100 mAs scan regardless of the angular coverage. The scanning speed can be reduced to less than 4 s when detectors become faster. Initial phantom studies showed good quality reconstructed images.\n\nCONCLUSIONS: A prototype s-DBT scanner has been developed and evaluated by retrofitting the Selenia rotating gantry DBT scanner with a spatially distributed CNT X-Ray Source arRay. Preliminary results show that it improves system spatial resolution substantially by eliminating image blur due to X-Ray focal spot motion. The scanner speed of s-DBT system is independent of angular coverage and can be increased with faster detector without image degration. The accelerated lifetime measurement demonstrated the long term stability of CNT X-Ray Source arRay with typical clinical operation lifetime over 3 years.
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Design and characterization of a spatially distributed multibeam field emission X-Ray Source for stationary digital breast tomosynthesis
Medical Physics, 2009Co-Authors: Xin Qian, Xiomara Calderon-colon, Tuyen Phan, Ramya Rajaram, David S. Lalush, Guang Yang, Jianping LuAbstract:Digital breast tomosynthesis (DBT) is a limited angle computed tomography technique that can distinguish tumors from its overlying breast tissues and has potentials for detection of cancers at a smaller size and earlier stage. Current prototype DBT scanners are based on the regular full-field digital mammography systems and require partial isocentric motion of an X-Ray tube over certain angular range to record the projection views. This prolongs the scanning time and, in turn, degrades the imaging quality due to motion blur. To mitigate the above limitations, the concept of a stationary DBT (s-DBT) scanner has been recently proposed based on the newly developed spatially distributed multibeam field emission X-Ray (MBFEX) Source technique using the carbon nanotube. The purpose of this article is to evaluate the performance of the 25-beam MBFEX Source arRay that has been designed and fabricated for the s-DBT system. The s-DBT system records all the projection images by electronically activating the multiple X-Ray beams from different viewing angles without any mechanical motion. The configuration of the MBFEX Source is close to the published values from the Siemens Mammomat system. The key issues including the X-Ray fluX, focal spot size, spatial resolution, scanning time, beam-to-beam consistency, and reliability are evaluated using the standard procedures. In this article, the authors describe the design and performance of a distributed X-Ray Source arRay specifically designed for the s-DBT system. They evaluate the emission current, current variation, lifetime, and focal spot sizes of the Source arRay. An emission current of up to 18 mA was obtained at 0.5 X 0.3 mm effective focal spot size. The eXperimentally measured focal spot sizes are comparable to that of a typical commercial mammography tube without motion blurring. Trade-off between the system spatial resolution, X-Ray fluX, and scanning time are also discussed. Projection images of a breast phantom were collected using the X-Ray Source arRay from 25 different viewing angles without motion. These preliminary results demonstrate the feasibility of the proposed s-DBT scanner. The technology has the potential to increase the resolution and reduce the imaging time for DBT. With the present design of 25 views, they demonstrated eXperimentally the feasibility of achieving 11 s scanning time at full detector resolution with 0.5 X 0.3 mm Source resolution without motion blur. The fleXibility in configuration of the X-Ray Source arRay will also allow system designers to consider imaging geometries that are difficult to achieve with the conventional single-Source rotating approach.
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stationary digital breast tomosynthesis system with a multi beam field emission X Ray Source arRay
Medical Imaging 2008 - Physics of Medical Imaging, 2008Co-Authors: Guang Yang, Shabana Sultana, Ramya Rajaram, David S. Lalush, Guohua Cao, Zhijun LiuAbstract:A stationary digital breast tomosynthesis (DBT) system using a carbon nanotube based multi-beam field emission X-Ray (MBFEX) Source has been designed. The purpose is to investigate the feasibility of reducing the total imaging time, simplifying the system design, and potentially improving the image quality comparing to the conventional DBT scanners. The MBFEX Source consists of 25 individually programmable X-Ray piXels which are evenly angular spaced covering a 48° field of view. The device acquires the projection images by electronically switching on and off the individual X-Ray piXels without mechanical motion of either the X-Ray Source or the detector. The designs of the X-Ray Source and the imaging system are presented. Some preliminary results are discussed.
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su ff i 40 a novel gantry free dbt system using a stationary multi beam field emission X Ray Source arRay based on carbon nanotubes cnts
Medical Physics, 2007Co-Authors: Guang Yang, David S. Lalush, Guohua Cao, R Rajaram, Jian Zhang, S Sultana, Otto ZhouAbstract:Purpose: To test the feasibility of a novel gantry‐free digital breast tomosynthesis (DBT) system using a stationary multi‐beam field emission X‐Ray Source arRay based on carbon nanotubes(CNTs) and to compare the system performance with the conventional devices.Method and Materials: Two tomosynthesisimagingsystems have been built: a compact model and a full scale model, which contain 9 and 25 individual X‐Ray piXels, respectively. The compact model can only image a partial breast phantom due to the limited span of the X‐Ray Source arRay and the small FOV of the detector. The full scale system is capable of full field digital mammography by utilizing a detector with 20‐cm FOV. The geometry of the full scale system is also comparable to the conventional DBT devices (refer to the supporting material). The system geometry, such as the Source to detector distance (SDD) and X‐Ray Source position, is calibrated. The slice images at different depths are reconstructed using ordered subset conveX (maXimum likelihood) method. The system performance is evaluated by measuring parameters such as MTF and SNR. Results: By eliminating the rotary gantry, the system design is simplified and the issue if image blurring due to X‐Ray Source motion is removed. The total scan time can potentially be further shortened with a faster detector readout speed. Conclusion: By eliminating the rotary gantry, the system noise and equipment cost of the tomosynthesisimagingsystem are reduced. The total scan time can be further shortened with faster detector readout speed. The novel stationary tomosysthesis system shows great potential in clinical imaging.
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multipleXing radiography using a carbon nanotube based X Ray Source
Applied Physics Letters, 2006Co-Authors: Jing Zhang, Guang Yang, S Chang, Jianping LuAbstract:Speed and temporal resolution are critical for tomographic imaging of objects in rapid motion. Current X-Ray scanners record images sequentially in the time domain. The serial approach limits their performance and demands increasingly high X-Ray peak power and gantry speed. We have developed a multipiXel carbon nanotube based field emission X-Ray Source that produces spatially and temporally modulated radiations. Using this device we show the feasibility of multipleXing radiography that enables simultaneous collection of multiple projection images using frequency multipleXing. A drastic increase of the speed and reduction of the X-Ray peak power are achieved without compromising the imaging quality.
Jianping Lu - One of the best experts on this subject based on the ideXlab platform.
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High resolution stationary digital breast tomosynthesis using distributed carbon nanotube X-Ray Source arRay
Medical Physics, 2012Co-Authors: Xin Qian, Emily Gidcumb, Xiomara Calderon-colon, Shabana Sultana, Andrew Tucker, Jianping Lu, Guang Yang, Derrek SpronkAbstract:PURPOSE: The purpose of this study is to investigate the feasibility of increasing the system spatial resolution and scanning speed of Hologic Selenia Dimensions digital breast tomosynthesis (DBT) scanner by replacing the rotating mammography X-Ray tube with a specially designed carbon nanotube (CNT) X-Ray Source arRay, which generates all the projection images needed for tomosynthesis reconstruction by electronically activating individual X-Ray Sources without any mechanical motion. The stationary digital breast tomosynthesis (s-DBT) design aims to (i) increase the system spatial resolution by eliminating image blurring due to X-Ray tube motion and (ii) reduce the scanning time. Low spatial resolution and long scanning time are the two main technical limitations of current DBT technology.\n\nMETHODS: A CNT X-Ray Source arRay was designed and evaluated against a set of targeted system performance parameters. Simulations were performed to determine the maXimum anode heat load at the desired focal spot size and to design the electron focusing optics. Field emission current from CNT cathode was measured for an eXtended period of time to determine the stable life time of CNT cathode for an eXpected clinical operation scenario. The Source arRay was manufactured, tested, and integrated with a Selenia scanner. An electronic control unit was developed to interface the Source arRay with the detection system and to scan and regulate X-Ray beams. The performance of the s-DBT system was evaluated using physical phantoms.\n\nRESULTS: The spatially distributed CNT X-Ray Source arRay comprised 31 individually addressable X-Ray Sources covering a 30 angular span with 1 pitch and an isotropic focal spot size of 0.6 mm at full width at half-maXimum. Stable operation at 28 kV(peak) anode voltage and 38 mA tube current was demonstrated with eXtended lifetime and good Source-to-Source consistency. For the standard imaging protocol of 15 views over 14, 100 mAs dose, and 2 × 2 detector binning, the projection resolution along the scanning direction increased from 4.0 cycles/mm [at 10% modulation-transfer-function (MTF)] in DBT to 5.1 cycles/mm in s-DBT at magnification factor of 1.08. The improvement is more pronounced for faster scanning speeds, wider angular coverage, and smaller detector piXel sizes. The scanning speed depends on the detector, the number of views, and the imaging dose. With 240 ms detector readout time, the s-DBT system scanning time is 6.3 s for a 15-view, 100 mAs scan regardless of the angular coverage. The scanning speed can be reduced to less than 4 s when detectors become faster. Initial phantom studies showed good quality reconstructed images.\n\nCONCLUSIONS: A prototype s-DBT scanner has been developed and evaluated by retrofitting the Selenia rotating gantry DBT scanner with a spatially distributed CNT X-Ray Source arRay. Preliminary results show that it improves system spatial resolution substantially by eliminating image blur due to X-Ray focal spot motion. The scanner speed of s-DBT system is independent of angular coverage and can be increased with faster detector without image degration. The accelerated lifetime measurement demonstrated the long term stability of CNT X-Ray Source arRay with typical clinical operation lifetime over 3 years.
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Design and characterization of a spatially distributed multibeam field emission X-Ray Source for stationary digital breast tomosynthesis
Medical Physics, 2009Co-Authors: Xin Qian, Xiomara Calderon-colon, Tuyen Phan, Ramya Rajaram, David S. Lalush, Guang Yang, Jianping LuAbstract:Digital breast tomosynthesis (DBT) is a limited angle computed tomography technique that can distinguish tumors from its overlying breast tissues and has potentials for detection of cancers at a smaller size and earlier stage. Current prototype DBT scanners are based on the regular full-field digital mammography systems and require partial isocentric motion of an X-Ray tube over certain angular range to record the projection views. This prolongs the scanning time and, in turn, degrades the imaging quality due to motion blur. To mitigate the above limitations, the concept of a stationary DBT (s-DBT) scanner has been recently proposed based on the newly developed spatially distributed multibeam field emission X-Ray (MBFEX) Source technique using the carbon nanotube. The purpose of this article is to evaluate the performance of the 25-beam MBFEX Source arRay that has been designed and fabricated for the s-DBT system. The s-DBT system records all the projection images by electronically activating the multiple X-Ray beams from different viewing angles without any mechanical motion. The configuration of the MBFEX Source is close to the published values from the Siemens Mammomat system. The key issues including the X-Ray fluX, focal spot size, spatial resolution, scanning time, beam-to-beam consistency, and reliability are evaluated using the standard procedures. In this article, the authors describe the design and performance of a distributed X-Ray Source arRay specifically designed for the s-DBT system. They evaluate the emission current, current variation, lifetime, and focal spot sizes of the Source arRay. An emission current of up to 18 mA was obtained at 0.5 X 0.3 mm effective focal spot size. The eXperimentally measured focal spot sizes are comparable to that of a typical commercial mammography tube without motion blurring. Trade-off between the system spatial resolution, X-Ray fluX, and scanning time are also discussed. Projection images of a breast phantom were collected using the X-Ray Source arRay from 25 different viewing angles without motion. These preliminary results demonstrate the feasibility of the proposed s-DBT scanner. The technology has the potential to increase the resolution and reduce the imaging time for DBT. With the present design of 25 views, they demonstrated eXperimentally the feasibility of achieving 11 s scanning time at full detector resolution with 0.5 X 0.3 mm Source resolution without motion blur. The fleXibility in configuration of the X-Ray Source arRay will also allow system designers to consider imaging geometries that are difficult to achieve with the conventional single-Source rotating approach.
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multipleXing radiography using a carbon nanotube based X Ray Source
Applied Physics Letters, 2006Co-Authors: Jing Zhang, Guang Yang, S Chang, Jianping LuAbstract:Speed and temporal resolution are critical for tomographic imaging of objects in rapid motion. Current X-Ray scanners record images sequentially in the time domain. The serial approach limits their performance and demands increasingly high X-Ray peak power and gantry speed. We have developed a multipiXel carbon nanotube based field emission X-Ray Source that produces spatially and temporally modulated radiations. Using this device we show the feasibility of multipleXing radiography that enables simultaneous collection of multiple projection images using frequency multipleXing. A drastic increase of the speed and reduction of the X-Ray peak power are achieved without compromising the imaging quality.
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Carbon nanotube based microfocus field emission X-Ray Source for microcomputed tomography
Applied Physics Letters, 2006Co-Authors: Zejian Liu, Y. Z. Lee, David Bordelon, Guang Yang, Jianping LuAbstract:Microcomputed tomography is now widely used for in vivo small animal imaging for cancer studies. Achieving high imaging quality of live objects requires the X-Ray Source to have both high spatial and temporal resolutions. Preliminary studies have shown that carbon nanotube ?CNT? based field emission X-Ray Source has significant intrinsic advantages over the conventional thermionic X-Ray tube including better temporal resolution and programmability. Here we report the design and characterization of a CNT based field emission X-Ray Source that also affords a high spatial resolution. The device uses modified asymmetric Einzel lenses for electron focusing and an elliptical shaped CNT cathode patterned by photolithography. Stable and small isotropic X-Ray focal spot sizes were obtained.
Otto Zhou - One of the best experts on this subject based on the ideXlab platform.
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stationary intraoral digital tomosynthesis using a carbon nanotube X Ray Source arRay
Dentomaxillofacial Radiology, 2015Co-Authors: Jing Shan, Andrew W. Tucker, Laurence R Gaalaas, Enrique Platin, Andre Mol, Otto ZhouAbstract:Objectives:Intraoral dental tomosynthesis and closely related tuned-aperture CT (TACT) are low-dose three-dimensional (3D) imaging modalities that have shown improved detection of multiple dental diseases. Clinical interest in implementing these technologies waned owing to their time-consuming nature. Recently developed carbon nanotube (CNT) X-Ray Sources allow rapid multi-image acquisition without mechanical motion, making tomosynthesis a clinically viable technique. The objective of this investigation was to evaluate the feasibility of and produce high-quality images from a digital tomosynthesis system employing CNT X-Ray technology.Methods:A test-bed stationary intraoral tomosynthesis unit was constructed using a CNT X-Ray Source arRay and a digital intraoral sensor. The Source-to-image distance was modified to make the system comparable in image resolution to current two-dimensional intraoral radiography imaging systems. Anthropomorphic phantoms containing teeth with simulated and real caries lesions ...
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stationary chest tomosynthesis using a carbon nanotube X Ray Source arRay a feasibility study
Physics in Medicine and Biology, 2015Co-Authors: Jing Shan, Andrew W. Tucker, Xiaohui Wang, David H Foos, Michael D Heath, Otto ZhouAbstract:Chest tomosynthesis is a low-dose, quasi-3D imaging modality that has been demonstrated to improve the detection sensitivity for small lung nodules, compared to 2D chest radiography. The purpose of this study is to investigate the feasibility and system requirements of stationary chest tomosynthesis (s-DCT) using a spatially distributed carbon nanotube (CNT) X-Ray Source arRay, where the projection images are collected by electronically activating individual X-Ray focal spots in the Source arRay without mechanical motion of the X-Ray Source, detector, or the patient. A bench-top system was constructed using an eXisting CNT field emission Source arRay and a flat panel detector. The tube output, beam quality, focal spot size, system in-plane and in-depth resolution were characterized. Tomosynthesis slices of an anthropomorphic chest phantom were reconstructed for image quality assessment. All 75 CNT Sources in the Source arRay were shown to operate reliably at 80 kVp and 5 mA tube current. Source-to-Source consistency in the tube current and focal spot size was observed. The incident air kerma reading per mAs was measured as 74.47 uGy mAs−1 at 100 cm. The first half value layer of the beam was 3 mm aluminum. An average focal spot size of 2.5 × 0.5 mm was measured. The system MTF was measured to be 1.7 cycles mm−1 along the scanning direction, and 3.4 cycles mm−1 perpendicular to the scanning direction. As the angular coverage of 11.6°–34°, the full width at half maXimum of the artifact spread function improved greatly from 9.5 to 5.2 mm. The reconstructed tomosynthesis slices clearly show airways and pulmonary vascular structures in the anthropomorphic lung phantom. The results show the CNT Source arRay is capable of generating sufficient dose for chest tomosynthesis imaging. The results obtained so far suggest an s-DCT using a distributed CNT X-Ray Source arRay is feasible.
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stationary chest tomosynthesis using a cnt X Ray Source arRay
Proceedings of SPIE, 2013Co-Authors: Jing Shan, Andrew W. Tucker, Pavel Chtcheprov, Xiaohui Wang, David H Foos, Michael D Heath, Otto ZhouAbstract:Chest tomosynthesis is an imaging modality that provides 3D sectional information of a patients thoracic cavity using limited angle X-Ray projections. Studies show that tomosynthesis can improve the detection of subtle lung nodules comparing to conventional radiography at a lower radiation dose than CT. In the conventional design, the projection images are collected by mechanically moving a single X-Ray Source to different viewing angles. We investigated the feasibility of stationary chest tomosynthesis using the distributed CNT X-Ray Source arRay technology, which can generate a scanning X-Ray beam without any mechanical motion. A proof-of-concept system was constructed using a short linear Source arRay and a at panel detector. The performance of the Source including the fluX was evaluated in the conteXt of chest imaging. The bench-top system was characterized and images of a chest phantom were acquired and reconstructed. The preliminary results demonstrate the feasibility of stationary chest tomosynthesis using the CNT X-Ray Source arRay technology.
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su ff i 40 a novel gantry free dbt system using a stationary multi beam field emission X Ray Source arRay based on carbon nanotubes cnts
Medical Physics, 2007Co-Authors: Guang Yang, David S. Lalush, Guohua Cao, R Rajaram, Jian Zhang, S Sultana, Otto ZhouAbstract:Purpose: To test the feasibility of a novel gantry‐free digital breast tomosynthesis (DBT) system using a stationary multi‐beam field emission X‐Ray Source arRay based on carbon nanotubes(CNTs) and to compare the system performance with the conventional devices.Method and Materials: Two tomosynthesisimagingsystems have been built: a compact model and a full scale model, which contain 9 and 25 individual X‐Ray piXels, respectively. The compact model can only image a partial breast phantom due to the limited span of the X‐Ray Source arRay and the small FOV of the detector. The full scale system is capable of full field digital mammography by utilizing a detector with 20‐cm FOV. The geometry of the full scale system is also comparable to the conventional DBT devices (refer to the supporting material). The system geometry, such as the Source to detector distance (SDD) and X‐Ray Source position, is calibrated. The slice images at different depths are reconstructed using ordered subset conveX (maXimum likelihood) method. The system performance is evaluated by measuring parameters such as MTF and SNR. Results: By eliminating the rotary gantry, the system design is simplified and the issue if image blurring due to X‐Ray Source motion is removed. The total scan time can potentially be further shortened with a faster detector readout speed. Conclusion: By eliminating the rotary gantry, the system noise and equipment cost of the tomosynthesisimagingsystem are reduced. The total scan time can be further shortened with faster detector readout speed. The novel stationary tomosysthesis system shows great potential in clinical imaging.
