Results for “LABORATORY ANIMALS” — Page 25

DOE OSTI2016

WE-FG-207A-03: Low-Dose Cone-Beam Breast CT: Physics and Technology Development

Mammography-based screening has been a valuable imaging tool for the early detection of non-palpable lesions and has contributed to significant reduction in breast cancer associated mortality. However, the breast imaging community recognizes that mammography is not ideal, and in particular is inferior for women with dense breasts. Also, the 2-D projection of a 3-D organ results in tissue superposition contributing to false-positives. The sensitivity of mammography is breast-density dependent. Its sensitivity, especially in dense breasts, is low due to overlapping tissue and the fact that normal breast tissue, benign lesions and breast cancers all have similar “densities”, making lesion detection more difficult. We ideally need 3-D imaging for imaging the 3-D breast. MRI is 3-D, whole breast ultrasound is 3-D, digital breast tomosynthesis is called 3-D but is really “pseudo 3-D” due to poor resolution along the depth-direction. Also, and importantly, we need to be able to administer intravenous contrast agents for optimal imaging, similar to other organ systems in the body. Dedicated breast CT allows for 3-D imaging of the uncompressed breast. In current designs, the patient is positioned prone on the table and the breast is pendant through an aperture and the scan takes approximately 10 seconds [O’Connell et al., AJR 195: 496–509, 2010]. Almost on the heels of the invention of CT itself, work began on the development of dedicated breast CT. These early breast CT systems were used in clinical trials and the results from comparative performance evaluation of breast CT and mammography for 1625 subjects were reported in 1980 [Chang et al., Cancer 46: 939–46, 1980]. However, the technological limitations at that time stymied clinical translation for decades. Subsequent to the landmark article in 2001 [Boone et al., Radiology 221: 657–67, 2001] that demonstrated the potential feasibility in terms of radiation dose, multiple research groups are actively investigating dedicated breast CT. The development of large-area flat-panel detectors with field-of-view sufficient to image the entire breast in each projection enabled development of flat-panel cone-beam breast CT. More recently, the availability of complimentary metal-oxide semiconductor (CMOS) detectors with lower system noise and finer pixel pitch, combined with the development of x-ray tubes with focal spot dimensions similar to mammography systems, has shown improved spatial resolution and could improve visualization of microcalcifications. These technological developments promise clinical translation of low-dose cone-beam breast CT. Dedicated photon-counting breast CT (pcBCT) systems represent a novel detector design, which provide high spatial resolution (∼ 100µm) and low mean glandular dose (MGD). The CdTe-based direct conversion detector technology was previously evaluated and confirmed by simulations and basic experiments on laboratory setups [Kalender et al., Eur Radiol 22: 1–8, 2012]. Measurements of dose, technical image quality parameters, and surgical specimens on a pcBCT scanner have been completed. Comparative evaluation of surgical specimens showed that pcBCT outperformed mammography and digital breast tomosynthesis with respect to 3D spatial resolution, detectability of calcifications, and soft tissue delineation. Major barriers to widespread clinical use of BCT relate to radiation dose, imaging of microcalcifications, and adequate coverage of breast tissue near the chest wall. Adequate chest wall coverage is also technically challenging but recent progress in x-ray tube, detector and table design now enables full breast coverage in the majority of patients. At this time, BCT has been deemed to be suitable for diagnostic imaging but not yet for screening. The mean glandular dose (MGD) from BCT has been reported to be between 5.7 to 27.8 mGy, and this range is comparable to, and within the range of, the MGD of 2.6 to 31.6 mGy in diagnostic mammography. In diagnostic studies, the median MGD from BCT and mammography were 12.6 and 11.1 mGy, respectively [Vedantham et al., Phys Med Biol. 58: 7921–36, 2013]. Moreover, in diagnostic imaging of the breast the location of the lesion is known and therefore characterization and not detection is by far the primary consideration. The role of bCT is particularly compelling for diagnostic imaging of the breast because it may replace in part the multiple mammographic views of the breast under vigorous compression. Other non-screening potential applications of bCT include the assessment of response to neoadjuvant therapy [Vedantham et al., J Clin Imaging Sci 4, 64, 2014] and pre-surgical evaluation. Learning Objectives: To understand the metrics used to evaluate screening and diagnostic imaging To understand the benefits and limitations of current clinical modalities To understand how breast CT can improve over current clinical modalities To note the early attempts to translate breast CT to the clinic in 1970s-1990s To understand the recent developments in low-dose cone-beam breast CT To understand the recent developments in photon-counting breast CT To understand the radiation dose, clinical translation, and recent developments in diagnostic imaging with breast CT Supported in part by NIH grants R21 CA134128, R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH or the NCI.; S. Vedantham, Funding sources: Supported in part by NIH/NCI grants R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH/NCI. Disclosures: Research collaboration with Koning Corporation, West Henrietta, NY. Conflicts of Interest: J. Boone, This research was supported in part by NIH grant R01CA181081; W. Kalender, WK is founder and CEO of CT Imaging GmbH Erlangen, Germany.; A. Karellas, NIH R21 CA134128, R01 CA128906, and R01 CA195512 and Research collaboration with Koning Corporation.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

WE-FG-207A-04: Performance Characteristics of Photon-Counting Breast CT

Mammography-based screening has been a valuable imaging tool for the early detection of non-palpable lesions and has contributed to significant reduction in breast cancer associated mortality. However, the breast imaging community recognizes that mammography is not ideal, and in particular is inferior for women with dense breasts. Also, the 2-D projection of a 3-D organ results in tissue superposition contributing to false-positives. The sensitivity of mammography is breast-density dependent. Its sensitivity, especially in dense breasts, is low due to overlapping tissue and the fact that normal breast tissue, benign lesions and breast cancers all have similar “densities”, making lesion detection more difficult. We ideally need 3-D imaging for imaging the 3-D breast. MRI is 3-D, whole breast ultrasound is 3-D, digital breast tomosynthesis is called 3-D but is really “pseudo 3-D” due to poor resolution along the depth-direction. Also, and importantly, we need to be able to administer intravenous contrast agents for optimal imaging, similar to other organ systems in the body. Dedicated breast CT allows for 3-D imaging of the uncompressed breast. In current designs, the patient is positioned prone on the table and the breast is pendant through an aperture and the scan takes approximately 10 seconds [O’Connell et al., AJR 195: 496–509, 2010]. Almost on the heels of the invention of CT itself, work began on the development of dedicated breast CT. These early breast CT systems were used in clinical trials and the results from comparative performance evaluation of breast CT and mammography for 1625 subjects were reported in 1980 [Chang et al., Cancer 46: 939–46, 1980]. However, the technological limitations at that time stymied clinical translation for decades. Subsequent to the landmark article in 2001 [Boone et al., Radiology 221: 657–67, 2001] that demonstrated the potential feasibility in terms of radiation dose, multiple research groups are actively investigating dedicated breast CT. The development of large-area flat-panel detectors with field-of-view sufficient to image the entire breast in each projection enabled development of flat-panel cone-beam breast CT. More recently, the availability of complimentary metal-oxide semiconductor (CMOS) detectors with lower system noise and finer pixel pitch, combined with the development of x-ray tubes with focal spot dimensions similar to mammography systems, has shown improved spatial resolution and could improve visualization of microcalcifications. These technological developments promise clinical translation of low-dose cone-beam breast CT. Dedicated photon-counting breast CT (pcBCT) systems represent a novel detector design, which provide high spatial resolution (∼ 100µm) and low mean glandular dose (MGD). The CdTe-based direct conversion detector technology was previously evaluated and confirmed by simulations and basic experiments on laboratory setups [Kalender et al., Eur Radiol 22: 1–8, 2012]. Measurements of dose, technical image quality parameters, and surgical specimens on a pcBCT scanner have been completed. Comparative evaluation of surgical specimens showed that pcBCT outperformed mammography and digital breast tomosynthesis with respect to 3D spatial resolution, detectability of calcifications, and soft tissue delineation. Major barriers to widespread clinical use of BCT relate to radiation dose, imaging of microcalcifications, and adequate coverage of breast tissue near the chest wall. Adequate chest wall coverage is also technically challenging but recent progress in x-ray tube, detector and table design now enables full breast coverage in the majority of patients. At this time, BCT has been deemed to be suitable for diagnostic imaging but not yet for screening. The mean glandular dose (MGD) from BCT has been reported to be between 5.7 to 27.8 mGy, and this range is comparable to, and within the range of, the MGD of 2.6 to 31.6 mGy in diagnostic mammography. In diagnostic studies, the median MGD from BCT and mammography were 12.6 and 11.1 mGy, respectively [Vedantham et al., Phys Med Biol. 58: 7921–36, 2013]. Moreover, in diagnostic imaging of the breast the location of the lesion is known and therefore characterization and not detection is by far the primary consideration. The role of bCT is particularly compelling for diagnostic imaging of the breast because it may replace in part the multiple mammographic views of the breast under vigorous compression. Other non-screening potential applications of bCT include the assessment of response to neoadjuvant therapy [Vedantham et al., J Clin Imaging Sci 4, 64, 2014] and pre-surgical evaluation. Learning Objectives: To understand the metrics used to evaluate screening and diagnostic imaging To understand the benefits and limitations of current clinical modalities To understand how breast CT can improve over current clinical modalities To note the early attempts to translate breast CT to the clinic in 1970s-1990s To understand the recent developments in low-dose cone-beam breast CT To understand the recent developments in photon-counting breast CT To understand the radiation dose, clinical translation, and recent developments in diagnostic imaging with breast CT Supported in part by NIH grants R21 CA134128, R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH or the NCI.; S. Vedantham, Funding sources: Supported in part by NIH/NCI grants R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH/NCI. Disclosures: Research collaboration with Koning Corporation, West Henrietta, NY. Conflicts of Interest: J. Boone, This research was supported in part by NIH grant R01CA181081; W. Kalender, WK is founder and CEO of CT Imaging GmbH Erlangen, Germany.; A. Karellas, NIH R21 CA134128, R01 CA128906, and R01 CA195512 and Research collaboration with Koning Corporation.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

WE-FG-207A-05: Dedicated Breast CT as a Diagnostic Imaging Tool: Physics and Clinical Feasibility

Mammography-based screening has been a valuable imaging tool for the early detection of non-palpable lesions and has contributed to significant reduction in breast cancer associated mortality. However, the breast imaging community recognizes that mammography is not ideal, and in particular is inferior for women with dense breasts. Also, the 2-D projection of a 3-D organ results in tissue superposition contributing to false-positives. The sensitivity of mammography is breast-density dependent. Its sensitivity, especially in dense breasts, is low due to overlapping tissue and the fact that normal breast tissue, benign lesions and breast cancers all have similar “densities”, making lesion detection more difficult. We ideally need 3-D imaging for imaging the 3-D breast. MRI is 3-D, whole breast ultrasound is 3-D, digital breast tomosynthesis is called 3-D but is really “pseudo 3-D” due to poor resolution along the depth-direction. Also, and importantly, we need to be able to administer intravenous contrast agents for optimal imaging, similar to other organ systems in the body. Dedicated breast CT allows for 3-D imaging of the uncompressed breast. In current designs, the patient is positioned prone on the table and the breast is pendant through an aperture and the scan takes approximately 10 seconds [O’Connell et al., AJR 195: 496–509, 2010]. Almost on the heels of the invention of CT itself, work began on the development of dedicated breast CT. These early breast CT systems were used in clinical trials and the results from comparative performance evaluation of breast CT and mammography for 1625 subjects were reported in 1980 [Chang et al., Cancer 46: 939–46, 1980]. However, the technological limitations at that time stymied clinical translation for decades. Subsequent to the landmark article in 2001 [Boone et al., Radiology 221: 657–67, 2001] that demonstrated the potential feasibility in terms of radiation dose, multiple research groups are actively investigating dedicated breast CT. The development of large-area flat-panel detectors with field-of-view sufficient to image the entire breast in each projection enabled development of flat-panel cone-beam breast CT. More recently, the availability of complimentary metal-oxide semiconductor (CMOS) detectors with lower system noise and finer pixel pitch, combined with the development of x-ray tubes with focal spot dimensions similar to mammography systems, has shown improved spatial resolution and could improve visualization of microcalcifications. These technological developments promise clinical translation of low-dose cone-beam breast CT. Dedicated photon-counting breast CT (pcBCT) systems represent a novel detector design, which provide high spatial resolution (∼ 100µm) and low mean glandular dose (MGD). The CdTe-based direct conversion detector technology was previously evaluated and confirmed by simulations and basic experiments on laboratory setups [Kalender et al., Eur Radiol 22: 1–8, 2012]. Measurements of dose, technical image quality parameters, and surgical specimens on a pcBCT scanner have been completed. Comparative evaluation of surgical specimens showed that pcBCT outperformed mammography and digital breast tomosynthesis with respect to 3D spatial resolution, detectability of calcifications, and soft tissue delineation. Major barriers to widespread clinical use of BCT relate to radiation dose, imaging of microcalcifications, and adequate coverage of breast tissue near the chest wall. Adequate chest wall coverage is also technically challenging but recent progress in x-ray tube, detector and table design now enables full breast coverage in the majority of patients. At this time, BCT has been deemed to be suitable for diagnostic imaging but not yet for screening. The mean glandular dose (MGD) from BCT has been reported to be between 5.7 to 27.8 mGy, and this range is comparable to, and within the range of, the MGD of 2.6 to 31.6 mGy in diagnostic mammography. In diagnostic studies, the median MGD from BCT and mammography were 12.6 and 11.1 mGy, respectively [Vedantham et al., Phys Med Biol. 58: 7921–36, 2013]. Moreover, in diagnostic imaging of the breast the location of the lesion is known and therefore characterization and not detection is by far the primary consideration. The role of bCT is particularly compelling for diagnostic imaging of the breast because it may replace in part the multiple mammographic views of the breast under vigorous compression. Other non-screening potential applications of bCT include the assessment of response to neoadjuvant therapy [Vedantham et al., J Clin Imaging Sci 4, 64, 2014] and pre-surgical evaluation. Learning Objectives: To understand the metrics used to evaluate screening and diagnostic imaging To understand the benefits and limitations of current clinical modalities To understand how breast CT can improve over current clinical modalities To note the early attempts to translate breast CT to the clinic in 1970s-1990s To understand the recent developments in low-dose cone-beam breast CT To understand the recent developments in photon-counting breast CT To understand the radiation dose, clinical translation, and recent developments in diagnostic imaging with breast CT Supported in part by NIH grants R21 CA134128, R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH or the NCI.; S. Vedantham, Funding sources: Supported in part by NIH/NCI grants R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH/NCI. Disclosures: Research collaboration with Koning Corporation, West Henrietta, NY. Conflicts of Interest: J. Boone, This research was supported in part by NIH grant R01CA181081; W. Kalender, WK is founder and CEO of CT Imaging GmbH Erlangen, Germany.; A. Karellas, NIH R21 CA134128, R01 CA128906, and R01 CA195512 and Research collaboration with Koning Corporation.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

WE-FG-207A-02: Why We Need Breast CT? - Clinical Perspective

Mammography-based screening has been a valuable imaging tool for the early detection of non-palpable lesions and has contributed to significant reduction in breast cancer associated mortality. However, the breast imaging community recognizes that mammography is not ideal, and in particular is inferior for women with dense breasts. Also, the 2-D projection of a 3-D organ results in tissue superposition contributing to false-positives. The sensitivity of mammography is breast-density dependent. Its sensitivity, especially in dense breasts, is low due to overlapping tissue and the fact that normal breast tissue, benign lesions and breast cancers all have similar “densities”, making lesion detection more difficult. We ideally need 3-D imaging for imaging the 3-D breast. MRI is 3-D, whole breast ultrasound is 3-D, digital breast tomosynthesis is called 3-D but is really “pseudo 3-D” due to poor resolution along the depth-direction. Also, and importantly, we need to be able to administer intravenous contrast agents for optimal imaging, similar to other organ systems in the body. Dedicated breast CT allows for 3-D imaging of the uncompressed breast. In current designs, the patient is positioned prone on the table and the breast is pendant through an aperture and the scan takes approximately 10 seconds [O’Connell et al., AJR 195: 496–509, 2010]. Almost on the heels of the invention of CT itself, work began on the development of dedicated breast CT. These early breast CT systems were used in clinical trials and the results from comparative performance evaluation of breast CT and mammography for 1625 subjects were reported in 1980 [Chang et al., Cancer 46: 939–46, 1980]. However, the technological limitations at that time stymied clinical translation for decades. Subsequent to the landmark article in 2001 [Boone et al., Radiology 221: 657–67, 2001] that demonstrated the potential feasibility in terms of radiation dose, multiple research groups are actively investigating dedicated breast CT. The development of large-area flat-panel detectors with field-of-view sufficient to image the entire breast in each projection enabled development of flat-panel cone-beam breast CT. More recently, the availability of complimentary metal-oxide semiconductor (CMOS) detectors with lower system noise and finer pixel pitch, combined with the development of x-ray tubes with focal spot dimensions similar to mammography systems, has shown improved spatial resolution and could improve visualization of microcalcifications. These technological developments promise clinical translation of low-dose cone-beam breast CT. Dedicated photon-counting breast CT (pcBCT) systems represent a novel detector design, which provide high spatial resolution (∼ 100µm) and low mean glandular dose (MGD). The CdTe-based direct conversion detector technology was previously evaluated and confirmed by simulations and basic experiments on laboratory setups [Kalender et al., Eur Radiol 22: 1–8, 2012]. Measurements of dose, technical image quality parameters, and surgical specimens on a pcBCT scanner have been completed. Comparative evaluation of surgical specimens showed that pcBCT outperformed mammography and digital breast tomosynthesis with respect to 3D spatial resolution, detectability of calcifications, and soft tissue delineation. Major barriers to widespread clinical use of BCT relate to radiation dose, imaging of microcalcifications, and adequate coverage of breast tissue near the chest wall. Adequate chest wall coverage is also technically challenging but recent progress in x-ray tube, detector and table design now enables full breast coverage in the majority of patients. At this time, BCT has been deemed to be suitable for diagnostic imaging but not yet for screening. The mean glandular dose (MGD) from BCT has been reported to be between 5.7 to 27.8 mGy, and this range is comparable to, and within the range of, the MGD of 2.6 to 31.6 mGy in diagnostic mammography. In diagnostic studies, the median MGD from BCT and mammography were 12.6 and 11.1 mGy, respectively [Vedantham et al., Phys Med Biol. 58: 7921–36, 2013]. Moreover, in diagnostic imaging of the breast the location of the lesion is known and therefore characterization and not detection is by far the primary consideration. The role of bCT is particularly compelling for diagnostic imaging of the breast because it may replace in part the multiple mammographic views of the breast under vigorous compression. Other non-screening potential applications of bCT include the assessment of response to neoadjuvant therapy [Vedantham et al., J Clin Imaging Sci 4, 64, 2014] and pre-surgical evaluation. Learning Objectives: To understand the metrics used to evaluate screening and diagnostic imaging To understand the benefits and limitations of current clinical modalities To understand how breast CT can improve over current clinical modalities To note the early attempts to translate breast CT to the clinic in 1970s-1990s To understand the recent developments in low-dose cone-beam breast CT To understand the recent developments in photon-counting breast CT To understand the radiation dose, clinical translation, and recent developments in diagnostic imaging with breast CT Supported in part by NIH grants R21 CA134128, R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH or the NCI.; S. Vedantham, Funding sources: Supported in part by NIH/NCI grants R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH/NCI. Disclosures: Research collaboration with Koning Corporation, West Henrietta, NY. Conflicts of Interest: J. Boone, This research was supported in part by NIH grant R01CA181081; W. Kalender, WK is founder and CEO of CT Imaging GmbH Erlangen, Germany.; A. Karellas, NIH R21 CA134128, R01 CA128906, and R01 CA195512 and Research collaboration with Koning Corporation.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2010

Role of Biochar in Mitigation of Climate Change

By virtue of the large fraction of the terrestrial carbon (C) cycle controlled by human activities, agroecosystems are both sources and sinks for greenhouse gases. Their potential role in mitigation of climate change thus depends on a dual strategy of decreasing greenhouse gas emissions while increasing sinks so that the net impact on climate warming is less than at present. Emissions of carbon dioxide, methane and nitrous oxide arise from various agricultural activities, ranging from land clearing to ploughing, fertilization, and animal husbandry. Reductions in these emissions can be achieved by decreasing the heterotrophic conversion of organic C to carbon dioxide, and by better management of agricultural waste streams to minimize release of methane and nitrous oxide. Current sinks include C stored in standing biomass and soil organic matter, and the oxidation of atmospheric methane by soil bacteria. These sinks can be enhanced by increasing net primary productivity, thereby actively withdrawing more carbon dioxide from the atmosphere, and by promoting more oxidation of methane by soils. Judicious biochar management may contribute to both strategies, reductions of emissions by agriculture and active withdrawal of atmospheric carbon dioxide, as part of a comprehensive scheme in agricultural and forestry watersheds. Biochar is a carbon-rich organic material generated by heating biomass in the absence, or under a limited supply, of oxygen. This so-called charring or pyrolysis process has been used to produce charcoal as a source of fuel for millennia. Recently, interest has grown in understanding the potential of this process to improve soil health by adding biochar as an amendment to soil, to manage agricultural and forestry wastes, to generate energy, to decrease net emissions of nitrous oxide and methane, and to store carbon (C). The main incentive of biochar systems for mitigation of climate change is to increase the stability of organic matter or biomass. This stability is achieved by the conversion of fresh organic materials, which mineralize comparatively quickly, into biochar, which mineralizes much more slowly. The difference between the mineralization of uncharred and charred material results in a greater amount of carbon storage in soils and a lower amount of carbon dioxide, the major greenhouse gas, in the atmosphere. The principle of creating and managing biochar systems may address multiple environmental constraints. Biochar may help not only in mitigating climate change, but also fulfill a role in management of agricultural and forestry wastes, enhancement of soil sustainability, and generation of energy. Pyrolysis is a comparatively low-technology intervention. Deployment on a global scale, however, must be done carefully if the full mitigation potential is to be reached. Critical aspects of a successful implementation are that: 1) the biochar is sufficiently stable to reduce greenhouse gases in the atmosphere for an appropriate length of time. 2) the storage of carbon as biochar in soil is not offset by greenhouse gas emissions along the value chain of the system, such as mineralization of soil carbon or emissions of other greenhouse gases (e.g., methane and nitrous oxide). 3) net emission reductions are achieved for the entire life cycle of the system including indirect land use. 4) the biochar product does not cause unwanted side effects in soil. 5) the handling and production of biochar are in compliance with health and safety standards and do not pose hurdles to implementation. and 6) the biochar system is financially viable. This chapter discusses these issues in separate sections, identifies knowledge gaps, and proposes a road map to fully evaluate an environmentally and socially safe exploration of the biochar potential to mitigate climate change if adopted widely around the world.

03 NATURAL GAS↗