{"status":"OK","msg":"Details loaded!","speaker":{"id":5,"speaker":"William W. Moses","sarx_lecture":"Positron Emission Tomography Instrumentation: Present Status and Future Directions","sarx_lecture_abstract":"Positron emission tomography (PET) is a nuclear medical imaging technique that is commonly used to image cancer, heart disease, and brain function. The past ~15 years have seen many advances in PET instrumentation. The fraction of the body that is imaged has expanded by an order of magnitude and x-ray CT scanners are now mounted in the same gantry as the PET camera so that anatomical images from CT can be fused with the functional information from PET (i.e., the PET image shows which tissue is cancerous, while the CT image shows where this cancer is located in the patient\u2019s body). Dual- modality systems containing a PET camera and a MRI scanner (magnetic resonance imaging, which provides anatomical images with better soft-tissue contrast than x-ray CT) are now commercially available. The efficiency for detecting the injected radiation has been increased dramatically, but this greatly increases the flux of radiation that the detectors must process, and so new scintillator materials capable of higher speed operation have been developed. PET cameras dedicated to imaging specific forms of cancer, such as breast cancer or prostate cancer, have also been developed. In the research arena, PET has been found to be extremely valuable for studying biological function in animals, especially mice. This has spurred the development of PET cameras optimized for imaging mice that boast spatial resolutions better than 1\u00a0mm fwhm. Time- of-flight PET, which reduces the statistical noise in the images, has experienced a major rebirth. Despite these impressive advances, the instrumentation still limits the performance of PET in many ways. In a typical PET study, only about 25% of the detected coincidences are \u201ctrue\u201d events\u2014the other 75% are background event either from events that have undergone Compton scatter in the patient (roughly 25% of the events) or random coincidences (up to 50% of the events). The 511\u00a0keV gamma rays from positron annihilation can penetrate a significant distance into the scintillator crystals before they interact and are detected, which degrades the spatial resolution. The amount of radiotracer that can be injected into the patient is limited by safety concerns (radiation dose), so statistical noise (due to detecting fewer events than desired) limits the image quality. For animal PET, it is very desirable to image awake (rather than anesthetized) animals, as the anesthesia can significantly alter biological function. Finally, work needs to be done on how to evaluate how improvements in instrumentation translate into improvements in clinical practice and patient care. This presentation will describe these recent advances in more detail, list the needs that are presently unmet, and illustrate how some evolving technologies may help to meet these needs.","earj_lecture":"","earj_lecture_abstract":"","country":"USA","institution":"Institute of Electrical and Electronics Engineers (USA)","earj":0,"sarx":1,"duration":30,"short_bio":"William Moses is a Senior Staff Scientist in the Molecular Biophysics and Integrated Biomaging Division at LBNL. Until recently, he headed of the Department of Cellular and Tissue Imaging, which focuses on radiotracer imaging, medical applications, optical microscopy, electron microscopy, and cryo-EM. His main research interest is the development of instrumentation for Radiation Detection and Imaging, primarily for Nuclear Medical Imaging (especially positron emission tomography or PET), although he has also led projects in Homeland Security and in Environmental Remediation & Climate Change. This includes development of: (1) new dense inorganic scintillators for gamma ray detection, (2) novel photodetectors for measuring scintillation light, (3) custom integrated circuits and electronics for reading out radiation sensors, (4) new detector designs and camera geometries, and (5) tomographic reconstruction algorithms for these and other novel designs. He is a Fellow of the IEEE (Institute of Electrical and Electronics Engineers), where he was recognized for the development and application of efficient, high-resolution position tomography, and is currently a member of the IEEE Board of Directors.","cvlink":"https:\/\/drive.google.com\/open?id=0B5OeqF_9a9c3WHJaTXBMS3lJTHM","picture":"http:\/\/sarx2016.nbcgib.uesc.br\/speaker\/5\/picture","email":"wwmoses@lbl.gov","cvfile":null,"created_at":"-0001-11-30 00:00:00","updated_at":"2016-08-22 17:00:50","lecture":"Positron Emission Tomography Instrumentation: Present Status and Future Directions","abstract":"Positron emission tomography (PET) is a nuclear medical imaging technique that is commonly used to image cancer, heart disease, and brain function. The past ~15 years have seen many advances in PET instrumentation. The fraction of the body that is imaged has expanded by an order of magnitude and x-ray CT scanners are now mounted in the same gantry as the PET camera so that anatomical images from CT can be fused with the functional information from PET (i.e., the PET image shows which tissue is cancerous, while the CT image shows where this cancer is located in the patient\u2019s body). Dual- modality systems containing a PET camera and a MRI scanner (magnetic resonance imaging, which provides anatomical images with better soft-tissue contrast than x-ray CT) are now commercially available. The efficiency for detecting the injected radiation has been increased dramatically, but this greatly increases the flux of radiation that the detectors must process, and so new scintillator materials capable of higher speed operation have been developed. PET cameras dedicated to imaging specific forms of cancer, such as breast cancer or prostate cancer, have also been developed. In the research arena, PET has been found to be extremely valuable for studying biological function in animals, especially mice. This has spurred the development of PET cameras optimized for imaging mice that boast spatial resolutions better than 1\u00a0mm fwhm. Time- of-flight PET, which reduces the statistical noise in the images, has experienced a major rebirth. Despite these impressive advances, the instrumentation still limits the performance of PET in many ways. In a typical PET study, only about 25% of the detected coincidences are \u201ctrue\u201d events\u2014the other 75% are background event either from events that have undergone Compton scatter in the patient (roughly 25% of the events) or random coincidences (up to 50% of the events). The 511\u00a0keV gamma rays from positron annihilation can penetrate a significant distance into the scintillator crystals before they interact and are detected, which degrades the spatial resolution. The amount of radiotracer that can be injected into the patient is limited by safety concerns (radiation dose), so statistical noise (due to detecting fewer events than desired) limits the image quality. For animal PET, it is very desirable to image awake (rather than anesthetized) animals, as the anesthesia can significantly alter biological function. Finally, work needs to be done on how to evaluate how improvements in instrumentation translate into improvements in clinical practice and patient care. This presentation will describe these recent advances in more detail, list the needs that are presently unmet, and illustrate how some evolving technologies may help to meet these needs."}}