Post Doc MR Research Scientist
Business Unit: Business Administration
Requisition Number: 225610
Primary Location: United States-Maryland-Beltsville
Assignment Category: Full-time regular
Experience Level: Entry level
Education Required Level: Doctorate Degree
Travel Required: 5%
At Siemens Healthineers, we are passionate about enabling healthcare professionals to deliver high quality patient care, and to do so affordably. A leading global healthcare company, Siemens Healthineers continues to strengthen our portfolio of medical imaging and laboratory diagnostics, while adding new offerings such as managed services, consulting, and healthcare IT services – as well as further technologies in the growing market for therapeutic and molecular diagnostics.
Siemens Healthineers develops innovations that support better patient outcomes with greater efficiencies, giving providers the confidence they need to meet the clinical, operational and financial challenges of a changing healthcare landscape.
The primary goal of this project is to optimize and improve multi-channel RF transmit technology for high field human MRI, in particular 7T and 11.7T (500MHz). These systems are owned by NIMH and NINDS and situated in the NMR research center at NIH. During 2015, multi-channel Siemens RF transmit technology will be installed on both systems as part of the initial purchase agreement. However, because these is rather novel technology that is not fully develop yet, and in the case of the 11.7T, not standard product, various optimizations and alterations will be required to fully exploited potential benefits.
The expected benefits of multichannel RF technology are the improved control of the excitation RF fields that are used for MRI signal generation. This will aid the uniformity of sensitivity and contrast, as well as minimize tissue heating associated with RF transmission. This is increasingly important at high field, where RF wavelength effects can severely limit the types of contrasts that can be generated within the safety constraints of tissue heating.
The researcher we envision to be working on this projects will be involved with various aspects of the practical implementation of multi-channel RF transmit technology for brain imaging. After an initial 3-6 months stage gaining experience with the hardware and software associated with this technology at Siemens Erlangen (Germany), the fellow will start developing protocols for safe operation at 7T, which will include simulation of the RF magnetic and electric fields. This likely will use technologies and methods currently available at Siemens and/or NIH. Next, the benefits of multichannel RF technology for clinical MRI protocols will be evaluated, including the development of optimized RF pulses for inversion, excitation, refocusing, and magnetization transfer experiments. This all will be done under the safety constraints of tissue heating, likely with the active monitoring of RF feedback signals. Additional, single- and multi-slice excitation pulses will be designed to perform gradient echo anatomical and functional imaging with optimized SNR and contrast uniformity.
While expertise is being developed at 7T, and after working out the safety aspects at this field strength, time will be dedicated to optimize the technology at 11.7T. This may also involve the development of multi-channel RF excitation coils, as it is not clear whether the 8-channel transmit/head array supplied by Siemens/Rapid Biomedical will provide optimal RF transmit efficiency as well as optimal RF receive sensitivity. In addition, combination of the Siemens transmit technology with on-coil RF amplifier technology developed at NIH is envisioned, and is expected to provide improved control of the RF fields to improve their uniformity in the brain.