“In the light of the moon a little egg lays on a leaf”[7]

Management of cabling connecting coil arrays to system remains the nightmare of RF-engineers. Coupling within arrays to cabling reduces performance, and coupling to transmit field causes high shield currents. Consequently, traps are placed on conductors. To provide high blocking, traps are rigid, large and often heavy, hindering flexibility. Instead of a few high blocking traps, we propose a distributed system of small, elastic traps.  We leverage self-shielded resonant toroids forming a caterpillar-like structure. We show that this design can attenuate shield currents while being robust to flexing.

High impedance coils (HICs) offer major advantages  for use during MRI-guided radiotherapy (MRIgRT), as they lack lumped elements that can attenuate radiation. Furthermore, their flexibility and low channel coupling simplify high-density array development and enable on-body placement.

Here, we present a fully functional 32-channel HIC array, confirmed its radiation transparency (radiolucency) and compared the imaging performance with the current clinical (LIC-based) array. 

Dosimetrically, no clinically significant attenuation was caused by the array. Imaging-wise, the prototype showed higher SNR values and lower g-factors, thus allowing for faster imaging. 

In conclusion, our 32-channel array can accelerate all imaging for MRIgRT applications.

Numerical simulations were used to design and evaluate antenna arrays for body imaging at 14T. Previously presented fractionated dipole designs for 7T and 10.5T were adapted for 14T. Pulse optimization was performed in volumes with different sizes. In general, the RF shim performance decreases at higher RF frequency. The performance of 14T arrays in ROIs located in the body center is further limited by local SAR limits, as the SAR efficiency ($$$B_1^+$$$ normalized to $$$\sqrt{\operatorname{SAR}_{10g,max}}$$$) is lower in the body center.