The evolution of clinical Magnetic Resonance Imaging (MRI) technology often exhibits a symbiotic relationship with respect to the research community and the clinical users. The individual building blocks of a MRI system usually reflect the state-of-the-art in their respective technologies and techniques. The rate of development and evolution is tempered both by the available technology and the physiological limits of the human body. As new technology becomes available, new insights are gained from the users and, from these new insights, further technologies and applications are born.
The evolution of the modern MRI system has taken a remarkable path. Along this path there have been many obstacles. In most cases the obstacles have been overcome by definitive technology developments (i.e. shielded gradient systems, phased array RF coils, parallel imaging, etc.) and in each case the solutions have opened the door to more advanced applications and, subsequently, a new set of limitations. Up until 2008 the conceptual design of the RF transmit and receive subsystems of an MRI system had remained largely unchanged. In 2008 MultiTransmit was
introduced into clinical MRI and, more recently, broadband signal digitization at the receiving coils.
MRI is also expanding its boundaries of application beyond pure clinical diagnosis. The evolution of sophisticated and rapid MR imaging techniques, combined with the unique properties of MRI, enables suitably adapted MRI systems to perform as a “digital camera” during real-time interventional and therapeutic procedures. In particular, MRI is already being used to guide focused ultrasound (FUS) ablative treatments with developments ongoing to realize MRI guided Radiotherapy treatment.
This presentation will start by addressing the basics of MRI, that make it the unique tool it has become, then focus on the recent technology developments in MRI RF transmission, signal reception and image guided therapy.
Dr. Paul R. Harvey is Fellow and Chief Engineer (Senior Director) for the global Magnetic Resonance Imaging (MRI) business of Philips Healthcare. Since joining Philips in 1999, Dr. Harvey has directed the system design for the multiple premium level MRI products produced by Philips. Dr. Harvey was also system architect for pre-development of the world’s first actively shielded high-field open MRI system (Panorama HFO, introduced 2004) and for the front-end
components of the world’s first digital broadband MRI system (Ingenia, introduced 2010).
The Philips Achieva 3.0 TX system pioneered the use of parallel RF transmission in clinical MRI. The technical innovation, known as “MultiTransmit”, was first described by Dr. Harvey in 2003. In recognition of the significant impact that the MultiTransmit innovation has brought both to Philips Healthcare and the field of MRI in general, Dr. Harvey and the development team were awarded the first Philips Technology Innovation Award in December 2010.
Dr. Harvey has filed more than 100 patent applications, all in the field of MRI and relating to hardware and software technologies used in many modern MRI systems. He has written numerous scientific articles and is regularly invited to conferences as a guest-speaker on MRI technology, innovation and safety.
From 1993 to 1999 Dr. Harvey worked as a Senior Physicist (MRI) for Elscint Ltd. Whilst at Elscint, Dr. Harvey was involved in all aspects of MRI system hardware and software design. During the same period Dr. Harvey patented the concept of the modular gradient system (1994) which was developed into what became known as “Twin Gradient” technology (launched at RSNA 1997). In 1998 GE Healthcare acquired the modular gradient system technology and intellectual property. This was introduced, in 2000, as the premium MRI product for GE Healthcare.
Dr. Harvey obtained his Ph.D. in physics from Nottingham University (UK) in 1991, under the supervision of the Nobel laureate professor Sir Peter Mansfield. During his research Dr. Harvey developed the very first implementation of whole-body Echo Volumar Imaging (EVI) utilizing a novel multi-resonant gradient system. Together with Prof. Mansfield, Dr. Harvey was among the first to establish and validate a more accurate description of peripheral nerve stimulation (PNS) in response to rapidly switched magnetic fields. These insights on PNS have since influenced the basis of the IEC and FDA guidelines on MRI safety.
Dr. Harvey has more than 25 years experience in the field of MRI, 20 of these in product development and innovation specializing in every aspect of the MR system design from gradient/magnet systems, RF coils/systems to imaging and reconstruction methods, system calibrations and safety mechanisms.
About the Medical Physics Lunchtime Seminar:
The Medical Physics Lunchtime
Seminar is normally held on the last Monday of every month (except Bank
holidays) between 1 and 2 pm. The seminar series is open to all and features
principal investigators in and collaborators with the Department of Medical
Physics and Bioengineering at UCL and UCLH. Staff and students within the
department are strongly encouraged to attend to find out more about the various
exciting activities going on in the department. The seminar series aims to introduce the career path of the speakers, cultivate a stronger identity within the department, share current research fields with the wider UCL community, and to inspire the next generation of
scientists and students. Enquiries: Dr Ilias Tachtsidis