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Fast-Field Cycling MRI: A new tool for enhanced diagnosis
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Abstracts / Physica Medica 32 (2016) 188–191
tumours. A time resolution of 200 ps corresponding to a spatial resolution of 3 cm along the Line of Response (LOR) in a dual-head system, allowing a direct (and therefore fast) 3-dimensional reconstruction through a limited number of angular projections only, and an efficient rejection of background coming from outside of the few cubic centimetres region of interest (ROI). The presentation will also emphasize on the number of challenges that have been addressed, both technically and clinically, which have led to the development and introduction of cutting edge technologies in three technological areas: scintillator performances and production methods, light transport and photo-detectors.
among urologists, even more than ICs. Most studies so far have shown lens opacities rather than frank cataract, but data from A Bomb survivors indicates that lens opacities have the potential to lead to cataract after several years of latent period. International Commission on Radiological Protection (ICRP) has reduced dose limits for occupational exposure for the eyes from 150 mSv/year to 20 mSv/year and this has been adopted by the European Commission in its BSS and also by the international BSS of IAEA. There is great momentum currently in large part of the world in this area. While the risk is real, the avoidance is also a real possibility. http://dx.doi.org/10.1016/j.ejmp.2016.07.334
http://dx.doi.org/10.1016/j.ejmp.2016.07.332
FAST-FIELD CYCLING MRI: A NEW TOOL FOR ENHANCED DIAGNOSIS Lionel Broche. University of Aberdeen, United Kingdom Fast Field-Cycling MRI (FFC MRI) is a major shift in MRI technology. It aims to explore how relaxation rates change with the magnetic field strength, an idea that has been successfully exploited in NMR for more than half a century and which is known to provide unique structural information on materials, non-invasively. Scaling up FFC NMR to whole-body MRI systems is a difficult technical challenge that has maintained a lock on this area of research for many years. Our research group has successfully lifted this lock and developed two whole-body FFC MRI scanners: one with a field range of 0.1 mT to 59 mT that has been used in clinical trials for several years and the other with a range of 20 uT to 0.2 T still under development. Our pilot studies, which use both FFC MRI and FFC NMR, have discovered new biomarkers in a range of diseases such as osteoarthritis, breast carcinoma, musculoskeletal sarcoma, obesity, liver fibrosis, thrombosis and others. These FFC MRI biomarkers can differentiate tissues that appear similar on conventional MRI devices thanks, in part, to the greater endogenous contrast present at lower magnetic fields but also due to patterns that emerge from the overall relaxation dispersion curves of these tissues. The latter provides unique insight into the structure of materials and is, we believe, a promising tool to characterise tissue remodelling. This presentation will focus on FFC MRI technology, how it differs from conventional MRI and the results obtained so far from our pilot studies.
USING GATE FOR IMAGING APPLICATIONS George Loudos. Technological Educational Institute of Athens, Greece GATE has been well validated by many groups over the past decade for several imaging applications, with particular emphasis in nuclear medicine (SPECT and PET), as well as X-ray and CT imaging. Although the initial focus of published studies was to demonstrate that GATE can accurately reproduce experimental results, the robustness of the toolkit allowed its application in different imaging studies such as: (a) optimization of detector geometry and components selection to design dedicated systems for particular applications; (b) production of imaging data to optimize reconstruction algorithms and correction techniques by separating penetrating, scattered and random events; (c) optimization of imaging protocols by allowing the in silico evaluation of alternative acquisition schemes; (d) exploitation of computational anthropomorphic phantoms to allow reproduction of clinical exams and study of alternative imaging protocols and (e) validation of motion and respiratory techniques by using anthropomorphic phantoms in combination with animal models. The current challenge is to now use GATE in order to provide answers to specific diseases and focused imaging problems, where the performance of imaging systems must be pushed to the limits. Taking into account the current shift of detector technology towards patient personalization, GATE and realistic human phantoms provide a valuable tool that overcomes several practical limitations (including cost) for the assessment of novel imaging systems and technologies. Several examples from recent EC projects show that GATE is a well validated tool, which is exploited in a continuously increasing number of imaging applications. http://dx.doi.org/10.1016/j.ejmp.2016.07.335
http://dx.doi.org/10.1016/j.ejmp.2016.07.333
RADIATION-INDUCED CATARACTS IN STAFF ENGAGED IN INTERVENTIONAL PROCEDURES Madan M. Rehani. Harvard Medical School, Massachusetts General Hospital, Boston and Duke University, Durham, USA Among the radiation effects currently of concern, cataract is the main possibility among interventionalists. Radiation induced eye lens opacities have been found in 1/3rd to half of the operators in interventional suites primarily among interventional cardiologists (ICs) but this may apply to interventional radiologists, electrophysiologists and vascular surgeons as well, who perform similar magnitude of work as ICs. Further, nurses in interventional suites who stay inside for most of the time when radiation beam is ON have been shown to have lens opacities. Data among other category of medical professionals like orthopaedic surgeons, urologists, gastroenterologists and anaesthetists is awaited but lack of use of protective means that is common, tends to indicate that they too may have significant risk. A recent study indicates higher doses to eye lens
USING GATE FOR RADIATION THERAPY APPLICATIONS Panagiotis Papadimitroulas. BET Solutions, Athens, Greece Monte Carlo (MC) simulations is a standard method for studying physical processes in medical physics, worldwide. GATE is an opensource platform for simulating imaging, radiotherapy (RT) and dosimetry applications in a user-friendly environment. In RT applications, during the treatment planning, it is essential to accurately assess the deposited energy and the absorbed dose per tissue or organ of interest, as well as the local statistical uncertainty. Several types of realistic dosimetric applications are described including: molecular radiotherapy, radio-immunotherapy, brachytherapy, particle and external beam therapy. GATE is a MC toolkit which is well validated and is widely accepted by the scientific community. More specifically, it has been efficiently used in several applications, such as Dose Point Kernels, Svalues, Brachytherapy parameters (anisotropy and radial dose function), and compared against a variety of MC codes which are considered as standard tools for decades. Furthermore, comparison studies
Abstracts / Physica Medica 32 (2016) 188–191
tumours. A time resolution of 200 ps corresponding to a spatial resolution of 3 cm along the Line of Response (LOR) in a dual-head system, allowing a direct (and therefore fast) 3-dimensional reconstruction through a limited number of angular projections only, and an efficient rejection of background coming from outside of the few cubic centimetres region of interest (ROI). The presentation will also emphasize on the number of challenges that have been addressed, both technically and clinically, which have led to the development and introduction of cutting edge technologies in three technological areas: scintillator performances and production methods, light transport and photo-detectors.
among urologists, even more than ICs. Most studies so far have shown lens opacities rather than frank cataract, but data from A Bomb survivors indicates that lens opacities have the potential to lead to cataract after several years of latent period. International Commission on Radiological Protection (ICRP) has reduced dose limits for occupational exposure for the eyes from 150 mSv/year to 20 mSv/year and this has been adopted by the European Commission in its BSS and also by the international BSS of IAEA. There is great momentum currently in large part of the world in this area. While the risk is real, the avoidance is also a real possibility. http://dx.doi.org/10.1016/j.ejmp.2016.07.334
http://dx.doi.org/10.1016/j.ejmp.2016.07.332
FAST-FIELD CYCLING MRI: A NEW TOOL FOR ENHANCED DIAGNOSIS Lionel Broche. University of Aberdeen, United Kingdom Fast Field-Cycling MRI (FFC MRI) is a major shift in MRI technology. It aims to explore how relaxation rates change with the magnetic field strength, an idea that has been successfully exploited in NMR for more than half a century and which is known to provide unique structural information on materials, non-invasively. Scaling up FFC NMR to whole-body MRI systems is a difficult technical challenge that has maintained a lock on this area of research for many years. Our research group has successfully lifted this lock and developed two whole-body FFC MRI scanners: one with a field range of 0.1 mT to 59 mT that has been used in clinical trials for several years and the other with a range of 20 uT to 0.2 T still under development. Our pilot studies, which use both FFC MRI and FFC NMR, have discovered new biomarkers in a range of diseases such as osteoarthritis, breast carcinoma, musculoskeletal sarcoma, obesity, liver fibrosis, thrombosis and others. These FFC MRI biomarkers can differentiate tissues that appear similar on conventional MRI devices thanks, in part, to the greater endogenous contrast present at lower magnetic fields but also due to patterns that emerge from the overall relaxation dispersion curves of these tissues. The latter provides unique insight into the structure of materials and is, we believe, a promising tool to characterise tissue remodelling. This presentation will focus on FFC MRI technology, how it differs from conventional MRI and the results obtained so far from our pilot studies.
USING GATE FOR IMAGING APPLICATIONS George Loudos. Technological Educational Institute of Athens, Greece GATE has been well validated by many groups over the past decade for several imaging applications, with particular emphasis in nuclear medicine (SPECT and PET), as well as X-ray and CT imaging. Although the initial focus of published studies was to demonstrate that GATE can accurately reproduce experimental results, the robustness of the toolkit allowed its application in different imaging studies such as: (a) optimization of detector geometry and components selection to design dedicated systems for particular applications; (b) production of imaging data to optimize reconstruction algorithms and correction techniques by separating penetrating, scattered and random events; (c) optimization of imaging protocols by allowing the in silico evaluation of alternative acquisition schemes; (d) exploitation of computational anthropomorphic phantoms to allow reproduction of clinical exams and study of alternative imaging protocols and (e) validation of motion and respiratory techniques by using anthropomorphic phantoms in combination with animal models. The current challenge is to now use GATE in order to provide answers to specific diseases and focused imaging problems, where the performance of imaging systems must be pushed to the limits. Taking into account the current shift of detector technology towards patient personalization, GATE and realistic human phantoms provide a valuable tool that overcomes several practical limitations (including cost) for the assessment of novel imaging systems and technologies. Several examples from recent EC projects show that GATE is a well validated tool, which is exploited in a continuously increasing number of imaging applications. http://dx.doi.org/10.1016/j.ejmp.2016.07.335
http://dx.doi.org/10.1016/j.ejmp.2016.07.333
RADIATION-INDUCED CATARACTS IN STAFF ENGAGED IN INTERVENTIONAL PROCEDURES Madan M. Rehani. Harvard Medical School, Massachusetts General Hospital, Boston and Duke University, Durham, USA Among the radiation effects currently of concern, cataract is the main possibility among interventionalists. Radiation induced eye lens opacities have been found in 1/3rd to half of the operators in interventional suites primarily among interventional cardiologists (ICs) but this may apply to interventional radiologists, electrophysiologists and vascular surgeons as well, who perform similar magnitude of work as ICs. Further, nurses in interventional suites who stay inside for most of the time when radiation beam is ON have been shown to have lens opacities. Data among other category of medical professionals like orthopaedic surgeons, urologists, gastroenterologists and anaesthetists is awaited but lack of use of protective means that is common, tends to indicate that they too may have significant risk. A recent study indicates higher doses to eye lens
USING GATE FOR RADIATION THERAPY APPLICATIONS Panagiotis Papadimitroulas. BET Solutions, Athens, Greece Monte Carlo (MC) simulations is a standard method for studying physical processes in medical physics, worldwide. GATE is an opensource platform for simulating imaging, radiotherapy (RT) and dosimetry applications in a user-friendly environment. In RT applications, during the treatment planning, it is essential to accurately assess the deposited energy and the absorbed dose per tissue or organ of interest, as well as the local statistical uncertainty. Several types of realistic dosimetric applications are described including: molecular radiotherapy, radio-immunotherapy, brachytherapy, particle and external beam therapy. GATE is a MC toolkit which is well validated and is widely accepted by the scientific community. More specifically, it has been efficiently used in several applications, such as Dose Point Kernels, Svalues, Brachytherapy parameters (anisotropy and radial dose function), and compared against a variety of MC codes which are considered as standard tools for decades. Furthermore, comparison studies