PROJECT SUMMARY/ABSTRACT The overall objective of TRD4 is to develop innovative engineering solutions required to support the other TRDs and various collaborative and service projects in this P41 NCBIB. One of the most important issues that needs to be addressed, particularly while developing new ultra-high field MR technologies, is to ensure the overall MR related safety of the technology. We propose a new method for evaluating the RF safety of custom-built coils using an automated EM field measurement system. The proposed approach will allow safety evaluation with low power settings in a comprehensive manner. Supra-linear gains are expected with increasing field strength, however achieving these SNR gains in real life is a challenging engineering problem. Design and implementation of new RF coil technologies are essential for this goal. We will focus on developing novel RF coil designs that combine different coil geometries (e.g. loops and non-uniform dielectric substrate dipoles or sleeve antennas). We will also utilize novel RF electronics concepts including miniaturized integrated circuit low noise amplifiers and coil clusters to improve coil performance. To enhance SNR we will explore new receiver concepts and will investigate the possibility of harvesting the sheath currents flowing on receive coaxial cable circuity to further improve SNR. Combining these approaches, we will aim to capture the physically achievable limits of SNR in UHF MRI. We will translate the extensive prior experience we have developing human brain and body as well as awake and anesthetize NHP array technology at 10.5T along with the more recent insights to optimally capture central and peripheral SNR towards the design of optimized multi-channel transceiver/receiver arrays for 16.4T/700 MHz studies of marmosets. Particularly promising and impactful here is the integration of field orientation insensitive miniature IC preamplifiers of sub- cm scale which allow for on-coil amplification without line-of-sight restrictions. Finally, we plan to expand this extensive UHF technology expertise and the associated cumulative gains towards multinuclear coil technology with the aim of simultaneous optimization of Efficiency and SNR for dual nuclei.