Speaker: Professor Robert H. Caverly Villanova University, Villanova, PA USA
Topic: RF Aspects of Magnetic Resonance Imaging
Abstract: This presentation will focus on some of the RF aspects of the MR process and MR scanners. The MR image construction process and the control of the various steps that manipulate the atomic nuclei to generate the final MR diagnostic image put demanding constraints on RF equipment capabilities and these will be discussed, along with a high-level overview of the various components making up conventional MRI systems. This high-level overview will include a look at various examples of transmit and receive RF systems and examples of transmit and receive coils that make up MR scanners and system diagrams for both the RF transmit and receive paths. The talk will then narrow in scope to look at how these RF coils are modeled and controlled in both transmit and receive states and how these components are used for transmit/receive switching and patient and equipment protection. The talk will conclude with a look at current research that will eventually find its way into clinical and research scanners
Biography: Dr. Robert H. Caverly received his Ph.D. degree in electrical engineering from The Johns Hopkins University, Baltimore, MD, in 1983. He has been a faculty member at Villanova University in the Department of Electrical and Computer Engineering since 1997 and is a Full Professor. Previously, he was a Professor for more than 14 years at the University of Massachusetts Dartmouth. Dr. Caverly's research interests are focused on the characterization of semiconductor devices such as PIN diodes and FETs in the microwave and RF control environment. He has published more than 100 journal and conference papers and is the author of the books Microwave and RF Semiconductor Control Device Modeling and CMOS RFIC Design Principles, both from Artech House. An IEEE Fellow, Dr. Caverly is an Associate Editor of the IEEE Microwave Magazine and serves on a number of MTT-S committees. His webpage is http://rcaverly.ece.villanova.edu/rcaverly/rcaverly.htm
Speaker: Professor Gerard C. van Rhoon Erasmus MC Cancer Institute, Rotterdam, Netherlands
Topic: Heating tumors to enhance effectiveness of radiotherapy and chemotherapy
Abstract: The use of heat to kill tumor cell goes back to ancient history with the first written reference found 3000BC in the Edwin Smith surgical papyrus. During the last decades the impressive benefits of adjuvant hyperthermia have been demonstrated in randomized trials, for locally advanced cervical cancer (doubling 3yrs overall survival (OS)), high risk soft tissue sarcoma (5yrs OS + 12%), nasopharyngeal cancer (3yrs +19% OS). The consistency of good results together with the observation that hyperthermia does not cause significant toxicity, demonstrate that hyperthermia is not just an anecdotal technology, but one that warrants continued investment and investigation. As with other technology based treatments the ability to apply a well-controlled, high quality treatment is essential for good clinical outcome. During the last decades, several major technological innovations have been implemented to facilitate the application of a high quality hyperthermia treatment. The development and implementation of advanced Hyperthermia treatment planning as part of clinical routine, helps strongly in decision making i.e. can the tumor be heated adequately, a-priori selection of the optimal device settings per individual patient, as well as on-line optimization for patient specific complaints during treatment. High quality monitoring of the temperature distribution in tumor and normal tissue during treatment remains a challenge, though non-invasive MR-Thermometry, especially when exploited to perform fast and patient specific, online calibration of temperature modeling, appears to be promising. Currently the application of hyperthermia is experiencing a growing interest among Urologists for the treatment of non-muscle invasive bladder cancer and Surgeons for the treatment of peritoneal carcinomatosis of colorectal cancer using hyperthermic intraperitoneal chemotherapy. Supported by a growing understanding of the biological mechanisms of how heat sensitize tumor cells for radiotherapy and chemotherapy, the development of smart temperature controlled drug carriers and continuous innovation of hyperthermia technology will lead to increased use of hyperthermia for cancer treatment.
Biography: Gerard van Rhoon, is a Professor at the Erasmus MC Cancer Institute, department Radiation Oncology and director of the Hyperthermia unit. He is trained as a physicist and obtained in 1994 his Ph.D. at the Lab. of Electromagnetic Research, Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology. He started his career in 1977 within the department of Experimental Radiotherapy of the Erasmus University as researcher involved in the application of whole body hyperthermia. In 2011 he was appointment as Professor in Physical Aspects of Electromagnetic Fields & Health 2011 at the Erasmus MC Cancer Institute. Within the Erasmus MC Cancer Institute he is PI of the Academic Center of Excellence of Minimal Invasive Image Guided Therapy. The research program focuses on development of electromagnetic technology for heating tumors with a specific aim at the improvement and assurance of the quality of the hyperthermia treatment. A strong focus of the research is on the assessment of critical parameters for the application of 3- dimensional treatment planning applied on-line during loco-regional deep and superficial heating including quantitative validation of treatment planning models. He has designed several high power RF measuring devices specifically for the measurement RF-fields in the near-field of RF-antennae. A recent achievement was the development of a new hyperthermia system, for the first time in history completely designed through EM modeling to safely and adequately heat tumors in the head and neck region. This research is now commercialized via a start-up company. His recent interest is the development of technology to enable thermal-ablation brachytherapy to treat patients using minimally invasive, precise therapy as a one stop-shop intervention using high quality, intelligent and augmented reality imaging guidance. He is the President of the European Society for Hyperthermic Oncology. Further, he is a senior editor of the Int. J. of Hyperthermia and auditor for Physics in Medicine and Biology. He is author of over 150 peer-reviewed publications and over 120 publications in books, proceedings and non-peer-reviewed journals. He is a frequently invited speaker at congresses on hyperthermia and bio-medical engineering. He has received the first Lund Science Award in 1987, the Dr. BB Singh Award and the ESHO-BSD award in 2008 and the Dr. Sugahara Award in 2012.
Speaker: Prof. Paul M. Meaney Dartmouth College, Hanover, NH, USA And Chalmers University of Technology, Göteborg, Sweden
Title: Log transformation – making microwave reconstructions more linear and implications for non-a priori information reconstructions for biomedical applications
Abstract: The log transformation is widely used in various parameter estimation problems and especially for imaging including optical coherence tomography (OCT) and X-ray CT. In fact, for X-ray CT, the technique would essentially not be possible without it. For these applications, the transformation makes the image reconstruction process more linear. A similar claim can be made for its use in microwave tomography. Phantom and animal experiments using microwave tomography for thermal imaging clearly demonstrate that its temperature tracking ability is nearly linear when the transformation is used. The preponderance of clinical microwave tomographic imaging has been applied to the problem of breast cancer imaging including screening and diagnosis along with the emerging challenge of monitoring tumor progression during neoadjuvant chemotherapy. In all of these imaging problems, the biggest problem encountered in microwave tomography and not in OCT or X-rat CT is that wavelengths are sufficiently small that phase wrapping becomes problematic. Essentially, if not considered properly, it is entirely possible for some measurement and computed field values to appear on different Riemann sheets in the complex domain. In fact, by not taking this natural feature of the fields into account, processing them as if they were always on the same portion of the complex plane can result in ambiguous solutions. For alternative techniques, various forms of a priori information can sometimes overcome these difficulties. In this presentation, simple and robust methods for unwrapping both the measured and computed phase values are discussed. These concepts draw heavily from the extensive phase unwrapping body of work from the MR field and conventional range finding radar techniques. The culmination of the synergism of these robust approaches is an algorithm that converges to a global minimum without the use of a prior information while utilizing economically few antennas, even for large, high contrast targets. This concept is unique within the microwave community and has been applied to numerous clinical examples including breast and bone imaging.
Biography: Dr. Paul Meaney received AB’s in Electrical Engineering and Computer Science from Brown University in 1982. He earned his Masters Degree in Microwave Engineering from the University of Massachusetts in 1985 and worked in the millimeter-wave industry at companies including Millitech, Aerojet Electrosystems and Alpha Industries. He received his PhD from Dartmouth College in 1995 and spent two years as a postdoctoral fellow including one year at the Royal Marsden Hospital in Sutton, England. His research has focused mainly on microwave tomography which exploits the many facets of dielectric properties in tissue and other media. His principle interest over the last decade has been in the area of breast cancer imaging where his group was the first to translate an actual system into the clinic. His team has published several clinical studies in various settings including: (a) breast cancer diagnosis, (b) breast cancer chemotherapy monitoring, (c) bone density imaging, and (d) temperature monitoring during thermal therapy. He has also explored various commercial spin-off concepts such as detecting explosive liquids and non-invasively testing whether a bottle of wine has gone bad. He has been a Professor at Dartmouth since 1997, a professor at Chalmers University of Technology, Gothenburg, Sweden since 2015, and is also President of Microwave Imaging System Technologies, Inc. which he co-founded with Dr. Keith Paulsen in 1995. Dr. Meaney holds 10 patents, has co-authored 70 peer-reviewed journal articles, co-written one textbook and presented numerous invited papers related to microwave imaging. Dr. Paul Meaney´s research has focused mainly on microwave tomography which exploits the many facets of dielectric properties in tissue and other media. His principle interest over the last decade has been in the area of breast cancer imaging where his group was the first to translate an actual system into the clinic. His team has published several clinical studies in various settings including: (a) breast cancer diagnosis, (b) breast cancer chemotherapy monitoring, (c) bone density imaging, and (d) temperature monitoring during thermal therapy. Dr. Meaney holds 10 patents, has co-authored 70 peer-reviewed journal articles, co-written one textbook and presented numerous invited papers related to microwave imaging.