The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform

Jamshid Maddahi - One of the best experts on this subject based on the ideXlab platform.

  • phantom evaluation of a cardiac spect vct system that uses a common set of Solid State Detectors for both emission and transmission scans
    Journal of Nuclear Cardiology, 2010
    Co-Authors: Chuanyong Bai, Richard Conwell, Hetal Babla, Joel Kindem, Michael Gurley, Romer De Los Santos, Rex Old, Samia Arram, Jamshid Maddahi
    Abstract:

    We developed a cardiac SPECT system (X-ACT) with low dose volume CT transmission-based attenuation correction (AC). Three Solid-State Detectors are configured to form a triple-head system for emission scans and reconfigured to form a 69-cm field-of-view detector arc for transmission scans. A near mono-energetic transmission line source is produced from the collimated fluorescence x-ray emitted from a lead target when the target is illuminated by a narrow polychromatic x-ray beam from an x-ray tube. Transmission scans can be completed in 1 min with insignificant patient dose (deep dose equivalent <5 μSv). We used phantom studies to evaluate (1) the accuracy of the reconstructed attenuation maps, (2) the effect of AC on image uniformity, and (3) the effect of AC on defect contrast (DC). The phantoms we used included an ACR phantom, an anthropomorphic phantom with a uniform cardiac insert, and an anthropomorphic phantom with two defects in the cardiac insert. The reconstructed attenuation coefficient of water at 140 keV was .150 ± .003/cm in the uniform region of the ACR phantom, .151 ± .003/cm and .151 ± .002/cm in the liver and cardiac regions of the anthropomorphic phantom. The ACR phantom images with AC showed correction of the bowing effect due to attenuation in the images without AC (NC). The 17-segment scores of the images of the uniform cardiac insert were 78.3 ± 6.5 before and 87.9 ± 3.3 after AC (average ± standard deviation). The inferior-to-anterior wall ratio and the septal-to-lateral wall ratio were .99 and 1.16 before and 1.02 and 1.00 after AC. The DC of the two defects was .528 and .156 before and .628 and .173 after AC. The X-ACT system generated accurate attenuation maps with 1-minute transmission scans. AC improved image quality and uniformity over NC.

  • a novel cardiac spect system with x ray based attenuation correction using the same Solid State Detectors for both emission and transmission scans
    The Journal of Nuclear Medicine, 2008
    Co-Authors: Richard Conwell, Chuanyong Bai, Joel Kindem, Jamshid Maddahi
    Abstract:

    256 Objectives: Radio-isotopic-source-based and CT-based approaches are the two standard approaches for performing attenuation correction (AC) in cardiac SPECT. Drawbacks of the first approach are (1) the transmission scans significantly increase the study time due to the limited strength of the transmission sources and/or the low count rate capability of conventional Anger Detectors and (2) the obtained attenuation maps are noisy. Drawbacks of the second approach include (1) the need for a completely different detector system and (2) high patient dose from CT scans. In this work, we employ a low-dose x-ray transmission source for transmission scans using high-count-rate-capable Solid-State Detectors that are also used for emission scans. This configuration enables high quality attenuation maps to be obtained with minimal increase in total study time and with insignificant added dose to the patient. Methods: An upright Solid-State camera with fan-beam collimators was used for both emission and transmission scans of an anthropomorphic phantom. For transmission scans, a collimated line source was formed using an x-ray generator, and positioned at the focal line of the collimators. The camera could handle count rates greater than 12 Mcps which allowed transmission scans to be finished in 30 seconds. Results: Phantom studies showed high quality attenuation maps and improved uniformity in the image of the cardiac insert with AC (87±4), compared to the image without AC(78±6). The transmission dose was less than an equivalent injected dose of 5 uCi of Tc-99m. Conclusions: We developed a new X-ray-Based transmission approach for AC in cardiac SPECT. High-quality transmission scans can be completed within one minute and with negligible patient dose.

Richard Conwell - One of the best experts on this subject based on the ideXlab platform.

  • Handling of Bad Pixels on Pixelated Solid State Detectors
    IEEE Transactions on Nuclear Science, 2013
    Co-Authors: Chuanyong Bai, Richard Conwell, Hetal Babla, Joel Kindem, Michael Gurley
    Abstract:

    Bad pixel correction on pixelated Solid-State Detectors typically uses the average of the direct neighboring pixels (AVG) to derive the value of a bad pixel. However, the AVG approach was suboptimal for high resolution imaging. Therefore, we developed a least gradient approach (LGA) in this work. In the LGA approach, the gradients of the image in a 5 × 5 box centered at the bad pixel were calculated along the two orthogonal and two diagonal directions. The value of the bad pixel was derived from the average of the two neighboring pixels along the direction in which the gradient was the least. For 18 cardiac SPECT studies, we added to the data randomly generated bad pixels and bad pixels in a specially designed pattern and then corrected the bad pixels using the AVG approach. Images reconstructed from the bad-pixel-free data and the bad-pixel-corrected data were compared. For high resolution imaging, we used line and bar phantom studies to evaluate the AVG and LGA approaches on a pixelated Solid-State gamma camera. Patient studies showed no visible qualitative or significant quantitative difference between the images reconstructed from the bad-pixel-free and bad-pixel-corrected data. The maximum segment change ranged from 0% to 7.4% with average of 3.6 for data with randomly generated bad pixels. Blind reading of the images by an expert nuclear cardiologist showed no diagnostic difference for any of the patients. The line phantom studies showed two bad pixels not corrected by the AVG approach but corrected by the LGA approach. Bar phantom studies showed ten bad pixels not corrected by the AVG approach. But 9 out the 10 bad pixels were corrected using the LGA approach. The commonly used averaging approach (AVG) was effective for cardiac SPECT imaging but the least gradient approach (LGA) developed in this work was more effective for high resolution imaging.

  • csi t1 pin Solid State Detectors for combined high resolution spect and ct imaging
    Nuclear Science Symposium and Medical Imaging Conference, 2010
    Co-Authors: Joel Kindem, Chuanyong Bai, Richard Conwell
    Abstract:

    We have developed a CsI(Tl)/PIN detector module for high resolution SPECT and low dose photon-counting CT imaging. Using the detector modules with 6.1mm pixels, we built a cardiac SPECT system with three detector heads. The detector heads form a triple-head (each 20×15cm), geometry for emission scans and reconfigure to form a large transaxial field-of-view (FOV) geometry for transmission scans using an x-ray based transmission source. Anthropomorphic phantom and patient data was used to evaluate the performance of the new cardiac SPECT camera. We then developed modules with 2.8mm pixel size to further improve the spatial resolution, improving energy resolution to 7.5%. Improved energy resolution was achieved by improving the crystal arrays, electronics and packaging of the module. Using the 2.8mm modules, we built a large FOV planar imager (39×31cm), and evaluated its emission performance with clinical studies and its CT performance with an anthropomorphic phantom. The count rate capability was 20kcps per detector pixel. The combined SPECT/CT scan was completed in 5 min, resulting in high quality and accuracy attenuation maps (μ H20 @140keV was 0.151+/−0.003/cm at ∼5μSv CT dose). The large FOV imager showed excellent clarity and high resolution for emission bone studies and demonstrated reconstructed CT image quality suitable for attenuation correction or image fusion and localization (∼150μSv CT dose).

  • phantom evaluation of a cardiac spect vct system that uses a common set of Solid State Detectors for both emission and transmission scans
    Journal of Nuclear Cardiology, 2010
    Co-Authors: Chuanyong Bai, Richard Conwell, Hetal Babla, Joel Kindem, Michael Gurley, Romer De Los Santos, Rex Old, Samia Arram, Jamshid Maddahi
    Abstract:

    We developed a cardiac SPECT system (X-ACT) with low dose volume CT transmission-based attenuation correction (AC). Three Solid-State Detectors are configured to form a triple-head system for emission scans and reconfigured to form a 69-cm field-of-view detector arc for transmission scans. A near mono-energetic transmission line source is produced from the collimated fluorescence x-ray emitted from a lead target when the target is illuminated by a narrow polychromatic x-ray beam from an x-ray tube. Transmission scans can be completed in 1 min with insignificant patient dose (deep dose equivalent <5 μSv). We used phantom studies to evaluate (1) the accuracy of the reconstructed attenuation maps, (2) the effect of AC on image uniformity, and (3) the effect of AC on defect contrast (DC). The phantoms we used included an ACR phantom, an anthropomorphic phantom with a uniform cardiac insert, and an anthropomorphic phantom with two defects in the cardiac insert. The reconstructed attenuation coefficient of water at 140 keV was .150 ± .003/cm in the uniform region of the ACR phantom, .151 ± .003/cm and .151 ± .002/cm in the liver and cardiac regions of the anthropomorphic phantom. The ACR phantom images with AC showed correction of the bowing effect due to attenuation in the images without AC (NC). The 17-segment scores of the images of the uniform cardiac insert were 78.3 ± 6.5 before and 87.9 ± 3.3 after AC (average ± standard deviation). The inferior-to-anterior wall ratio and the septal-to-lateral wall ratio were .99 and 1.16 before and 1.02 and 1.00 after AC. The DC of the two defects was .528 and .156 before and .628 and .173 after AC. The X-ACT system generated accurate attenuation maps with 1-minute transmission scans. AC improved image quality and uniformity over NC.

  • a novel cardiac spect system with x ray based attenuation correction using the same Solid State Detectors for both emission and transmission scans
    The Journal of Nuclear Medicine, 2008
    Co-Authors: Richard Conwell, Chuanyong Bai, Joel Kindem, Jamshid Maddahi
    Abstract:

    256 Objectives: Radio-isotopic-source-based and CT-based approaches are the two standard approaches for performing attenuation correction (AC) in cardiac SPECT. Drawbacks of the first approach are (1) the transmission scans significantly increase the study time due to the limited strength of the transmission sources and/or the low count rate capability of conventional Anger Detectors and (2) the obtained attenuation maps are noisy. Drawbacks of the second approach include (1) the need for a completely different detector system and (2) high patient dose from CT scans. In this work, we employ a low-dose x-ray transmission source for transmission scans using high-count-rate-capable Solid-State Detectors that are also used for emission scans. This configuration enables high quality attenuation maps to be obtained with minimal increase in total study time and with insignificant added dose to the patient. Methods: An upright Solid-State camera with fan-beam collimators was used for both emission and transmission scans of an anthropomorphic phantom. For transmission scans, a collimated line source was formed using an x-ray generator, and positioned at the focal line of the collimators. The camera could handle count rates greater than 12 Mcps which allowed transmission scans to be finished in 30 seconds. Results: Phantom studies showed high quality attenuation maps and improved uniformity in the image of the cardiac insert with AC (87±4), compared to the image without AC(78±6). The transmission dose was less than an equivalent injected dose of 5 uCi of Tc-99m. Conclusions: We developed a new X-ray-Based transmission approach for AC in cardiac SPECT. High-quality transmission scans can be completed within one minute and with negligible patient dose.

Chuanyong Bai - One of the best experts on this subject based on the ideXlab platform.

  • Handling of Bad Pixels on Pixelated Solid State Detectors
    IEEE Transactions on Nuclear Science, 2013
    Co-Authors: Chuanyong Bai, Richard Conwell, Hetal Babla, Joel Kindem, Michael Gurley
    Abstract:

    Bad pixel correction on pixelated Solid-State Detectors typically uses the average of the direct neighboring pixels (AVG) to derive the value of a bad pixel. However, the AVG approach was suboptimal for high resolution imaging. Therefore, we developed a least gradient approach (LGA) in this work. In the LGA approach, the gradients of the image in a 5 × 5 box centered at the bad pixel were calculated along the two orthogonal and two diagonal directions. The value of the bad pixel was derived from the average of the two neighboring pixels along the direction in which the gradient was the least. For 18 cardiac SPECT studies, we added to the data randomly generated bad pixels and bad pixels in a specially designed pattern and then corrected the bad pixels using the AVG approach. Images reconstructed from the bad-pixel-free data and the bad-pixel-corrected data were compared. For high resolution imaging, we used line and bar phantom studies to evaluate the AVG and LGA approaches on a pixelated Solid-State gamma camera. Patient studies showed no visible qualitative or significant quantitative difference between the images reconstructed from the bad-pixel-free and bad-pixel-corrected data. The maximum segment change ranged from 0% to 7.4% with average of 3.6 for data with randomly generated bad pixels. Blind reading of the images by an expert nuclear cardiologist showed no diagnostic difference for any of the patients. The line phantom studies showed two bad pixels not corrected by the AVG approach but corrected by the LGA approach. Bar phantom studies showed ten bad pixels not corrected by the AVG approach. But 9 out the 10 bad pixels were corrected using the LGA approach. The commonly used averaging approach (AVG) was effective for cardiac SPECT imaging but the least gradient approach (LGA) developed in this work was more effective for high resolution imaging.

  • csi t1 pin Solid State Detectors for combined high resolution spect and ct imaging
    Nuclear Science Symposium and Medical Imaging Conference, 2010
    Co-Authors: Joel Kindem, Chuanyong Bai, Richard Conwell
    Abstract:

    We have developed a CsI(Tl)/PIN detector module for high resolution SPECT and low dose photon-counting CT imaging. Using the detector modules with 6.1mm pixels, we built a cardiac SPECT system with three detector heads. The detector heads form a triple-head (each 20×15cm), geometry for emission scans and reconfigure to form a large transaxial field-of-view (FOV) geometry for transmission scans using an x-ray based transmission source. Anthropomorphic phantom and patient data was used to evaluate the performance of the new cardiac SPECT camera. We then developed modules with 2.8mm pixel size to further improve the spatial resolution, improving energy resolution to 7.5%. Improved energy resolution was achieved by improving the crystal arrays, electronics and packaging of the module. Using the 2.8mm modules, we built a large FOV planar imager (39×31cm), and evaluated its emission performance with clinical studies and its CT performance with an anthropomorphic phantom. The count rate capability was 20kcps per detector pixel. The combined SPECT/CT scan was completed in 5 min, resulting in high quality and accuracy attenuation maps (μ H20 @140keV was 0.151+/−0.003/cm at ∼5μSv CT dose). The large FOV imager showed excellent clarity and high resolution for emission bone studies and demonstrated reconstructed CT image quality suitable for attenuation correction or image fusion and localization (∼150μSv CT dose).

  • phantom evaluation of a cardiac spect vct system that uses a common set of Solid State Detectors for both emission and transmission scans
    Journal of Nuclear Cardiology, 2010
    Co-Authors: Chuanyong Bai, Richard Conwell, Hetal Babla, Joel Kindem, Michael Gurley, Romer De Los Santos, Rex Old, Samia Arram, Jamshid Maddahi
    Abstract:

    We developed a cardiac SPECT system (X-ACT) with low dose volume CT transmission-based attenuation correction (AC). Three Solid-State Detectors are configured to form a triple-head system for emission scans and reconfigured to form a 69-cm field-of-view detector arc for transmission scans. A near mono-energetic transmission line source is produced from the collimated fluorescence x-ray emitted from a lead target when the target is illuminated by a narrow polychromatic x-ray beam from an x-ray tube. Transmission scans can be completed in 1 min with insignificant patient dose (deep dose equivalent <5 μSv). We used phantom studies to evaluate (1) the accuracy of the reconstructed attenuation maps, (2) the effect of AC on image uniformity, and (3) the effect of AC on defect contrast (DC). The phantoms we used included an ACR phantom, an anthropomorphic phantom with a uniform cardiac insert, and an anthropomorphic phantom with two defects in the cardiac insert. The reconstructed attenuation coefficient of water at 140 keV was .150 ± .003/cm in the uniform region of the ACR phantom, .151 ± .003/cm and .151 ± .002/cm in the liver and cardiac regions of the anthropomorphic phantom. The ACR phantom images with AC showed correction of the bowing effect due to attenuation in the images without AC (NC). The 17-segment scores of the images of the uniform cardiac insert were 78.3 ± 6.5 before and 87.9 ± 3.3 after AC (average ± standard deviation). The inferior-to-anterior wall ratio and the septal-to-lateral wall ratio were .99 and 1.16 before and 1.02 and 1.00 after AC. The DC of the two defects was .528 and .156 before and .628 and .173 after AC. The X-ACT system generated accurate attenuation maps with 1-minute transmission scans. AC improved image quality and uniformity over NC.

  • a novel cardiac spect system with x ray based attenuation correction using the same Solid State Detectors for both emission and transmission scans
    The Journal of Nuclear Medicine, 2008
    Co-Authors: Richard Conwell, Chuanyong Bai, Joel Kindem, Jamshid Maddahi
    Abstract:

    256 Objectives: Radio-isotopic-source-based and CT-based approaches are the two standard approaches for performing attenuation correction (AC) in cardiac SPECT. Drawbacks of the first approach are (1) the transmission scans significantly increase the study time due to the limited strength of the transmission sources and/or the low count rate capability of conventional Anger Detectors and (2) the obtained attenuation maps are noisy. Drawbacks of the second approach include (1) the need for a completely different detector system and (2) high patient dose from CT scans. In this work, we employ a low-dose x-ray transmission source for transmission scans using high-count-rate-capable Solid-State Detectors that are also used for emission scans. This configuration enables high quality attenuation maps to be obtained with minimal increase in total study time and with insignificant added dose to the patient. Methods: An upright Solid-State camera with fan-beam collimators was used for both emission and transmission scans of an anthropomorphic phantom. For transmission scans, a collimated line source was formed using an x-ray generator, and positioned at the focal line of the collimators. The camera could handle count rates greater than 12 Mcps which allowed transmission scans to be finished in 30 seconds. Results: Phantom studies showed high quality attenuation maps and improved uniformity in the image of the cardiac insert with AC (87±4), compared to the image without AC(78±6). The transmission dose was less than an equivalent injected dose of 5 uCi of Tc-99m. Conclusions: We developed a new X-ray-Based transmission approach for AC in cardiac SPECT. High-quality transmission scans can be completed within one minute and with negligible patient dose.

Joel Kindem - One of the best experts on this subject based on the ideXlab platform.

  • Handling of Bad Pixels on Pixelated Solid State Detectors
    IEEE Transactions on Nuclear Science, 2013
    Co-Authors: Chuanyong Bai, Richard Conwell, Hetal Babla, Joel Kindem, Michael Gurley
    Abstract:

    Bad pixel correction on pixelated Solid-State Detectors typically uses the average of the direct neighboring pixels (AVG) to derive the value of a bad pixel. However, the AVG approach was suboptimal for high resolution imaging. Therefore, we developed a least gradient approach (LGA) in this work. In the LGA approach, the gradients of the image in a 5 × 5 box centered at the bad pixel were calculated along the two orthogonal and two diagonal directions. The value of the bad pixel was derived from the average of the two neighboring pixels along the direction in which the gradient was the least. For 18 cardiac SPECT studies, we added to the data randomly generated bad pixels and bad pixels in a specially designed pattern and then corrected the bad pixels using the AVG approach. Images reconstructed from the bad-pixel-free data and the bad-pixel-corrected data were compared. For high resolution imaging, we used line and bar phantom studies to evaluate the AVG and LGA approaches on a pixelated Solid-State gamma camera. Patient studies showed no visible qualitative or significant quantitative difference between the images reconstructed from the bad-pixel-free and bad-pixel-corrected data. The maximum segment change ranged from 0% to 7.4% with average of 3.6 for data with randomly generated bad pixels. Blind reading of the images by an expert nuclear cardiologist showed no diagnostic difference for any of the patients. The line phantom studies showed two bad pixels not corrected by the AVG approach but corrected by the LGA approach. Bar phantom studies showed ten bad pixels not corrected by the AVG approach. But 9 out the 10 bad pixels were corrected using the LGA approach. The commonly used averaging approach (AVG) was effective for cardiac SPECT imaging but the least gradient approach (LGA) developed in this work was more effective for high resolution imaging.

  • csi t1 pin Solid State Detectors for combined high resolution spect and ct imaging
    Nuclear Science Symposium and Medical Imaging Conference, 2010
    Co-Authors: Joel Kindem, Chuanyong Bai, Richard Conwell
    Abstract:

    We have developed a CsI(Tl)/PIN detector module for high resolution SPECT and low dose photon-counting CT imaging. Using the detector modules with 6.1mm pixels, we built a cardiac SPECT system with three detector heads. The detector heads form a triple-head (each 20×15cm), geometry for emission scans and reconfigure to form a large transaxial field-of-view (FOV) geometry for transmission scans using an x-ray based transmission source. Anthropomorphic phantom and patient data was used to evaluate the performance of the new cardiac SPECT camera. We then developed modules with 2.8mm pixel size to further improve the spatial resolution, improving energy resolution to 7.5%. Improved energy resolution was achieved by improving the crystal arrays, electronics and packaging of the module. Using the 2.8mm modules, we built a large FOV planar imager (39×31cm), and evaluated its emission performance with clinical studies and its CT performance with an anthropomorphic phantom. The count rate capability was 20kcps per detector pixel. The combined SPECT/CT scan was completed in 5 min, resulting in high quality and accuracy attenuation maps (μ H20 @140keV was 0.151+/−0.003/cm at ∼5μSv CT dose). The large FOV imager showed excellent clarity and high resolution for emission bone studies and demonstrated reconstructed CT image quality suitable for attenuation correction or image fusion and localization (∼150μSv CT dose).

  • phantom evaluation of a cardiac spect vct system that uses a common set of Solid State Detectors for both emission and transmission scans
    Journal of Nuclear Cardiology, 2010
    Co-Authors: Chuanyong Bai, Richard Conwell, Hetal Babla, Joel Kindem, Michael Gurley, Romer De Los Santos, Rex Old, Samia Arram, Jamshid Maddahi
    Abstract:

    We developed a cardiac SPECT system (X-ACT) with low dose volume CT transmission-based attenuation correction (AC). Three Solid-State Detectors are configured to form a triple-head system for emission scans and reconfigured to form a 69-cm field-of-view detector arc for transmission scans. A near mono-energetic transmission line source is produced from the collimated fluorescence x-ray emitted from a lead target when the target is illuminated by a narrow polychromatic x-ray beam from an x-ray tube. Transmission scans can be completed in 1 min with insignificant patient dose (deep dose equivalent <5 μSv). We used phantom studies to evaluate (1) the accuracy of the reconstructed attenuation maps, (2) the effect of AC on image uniformity, and (3) the effect of AC on defect contrast (DC). The phantoms we used included an ACR phantom, an anthropomorphic phantom with a uniform cardiac insert, and an anthropomorphic phantom with two defects in the cardiac insert. The reconstructed attenuation coefficient of water at 140 keV was .150 ± .003/cm in the uniform region of the ACR phantom, .151 ± .003/cm and .151 ± .002/cm in the liver and cardiac regions of the anthropomorphic phantom. The ACR phantom images with AC showed correction of the bowing effect due to attenuation in the images without AC (NC). The 17-segment scores of the images of the uniform cardiac insert were 78.3 ± 6.5 before and 87.9 ± 3.3 after AC (average ± standard deviation). The inferior-to-anterior wall ratio and the septal-to-lateral wall ratio were .99 and 1.16 before and 1.02 and 1.00 after AC. The DC of the two defects was .528 and .156 before and .628 and .173 after AC. The X-ACT system generated accurate attenuation maps with 1-minute transmission scans. AC improved image quality and uniformity over NC.

  • a novel cardiac spect system with x ray based attenuation correction using the same Solid State Detectors for both emission and transmission scans
    The Journal of Nuclear Medicine, 2008
    Co-Authors: Richard Conwell, Chuanyong Bai, Joel Kindem, Jamshid Maddahi
    Abstract:

    256 Objectives: Radio-isotopic-source-based and CT-based approaches are the two standard approaches for performing attenuation correction (AC) in cardiac SPECT. Drawbacks of the first approach are (1) the transmission scans significantly increase the study time due to the limited strength of the transmission sources and/or the low count rate capability of conventional Anger Detectors and (2) the obtained attenuation maps are noisy. Drawbacks of the second approach include (1) the need for a completely different detector system and (2) high patient dose from CT scans. In this work, we employ a low-dose x-ray transmission source for transmission scans using high-count-rate-capable Solid-State Detectors that are also used for emission scans. This configuration enables high quality attenuation maps to be obtained with minimal increase in total study time and with insignificant added dose to the patient. Methods: An upright Solid-State camera with fan-beam collimators was used for both emission and transmission scans of an anthropomorphic phantom. For transmission scans, a collimated line source was formed using an x-ray generator, and positioned at the focal line of the collimators. The camera could handle count rates greater than 12 Mcps which allowed transmission scans to be finished in 30 seconds. Results: Phantom studies showed high quality attenuation maps and improved uniformity in the image of the cardiac insert with AC (87±4), compared to the image without AC(78±6). The transmission dose was less than an equivalent injected dose of 5 uCi of Tc-99m. Conclusions: We developed a new X-ray-Based transmission approach for AC in cardiac SPECT. High-quality transmission scans can be completed within one minute and with negligible patient dose.

Eric A. Wulf - One of the best experts on this subject based on the ideXlab platform.

  • An advanced Compton telescope based on thick, position-sensitive Solid-State Detectors
    New Astronomy Reviews, 2003
    Co-Authors: James D. Kurfess, W. N. Johnson, Richard A. Kroeger, E.i. Novikova, Bernard F. Phlips, M. S. Strickman, Eric A. Wulf
    Abstract:

    Abstract The development of high-resolution, position-sensitive Solid-State Detectors enables γ-ray instruments with improved sensitivity and imaging capabilities. For γ-ray astronomy, an improvement in sensitivity of 20–50 over previous missions is anticipated with the Advanced Compton Telescope (ACT) mission. The γ-ray astrophysics group at NRL has been developing germanium strip Detectors for several years. We have shown that 3D locations for γ-ray interactions can be determined with mm accuracy, and have also demonstrated imaging capability within a single germanium strip detector and in detector arrays. Based on the realization that three Compton interactions would enable the energy and direction cone of the incident γ-ray to be determined, even when the total incident γ-ray energy is not deposited in the detector, we have also initiated work on thick silicon strip Detectors. We are investigating the use of both thick Si(Li) and thick intrinsic silicon Detectors. Progress on this work, including initial tests of the multiple-Compton imaging technique, is presented.