Wearable Coil Using Copper Traces on Fabric for MRI at 3T

Objectives: Conductors used for fabrication of coils on fabric substrates suffer from inherent losses because of the combination of the metallic core with other non-conductive materials, thus limiting the SNR achieved. The purpose of this work is to demonstrate the application of copper traces on a fabric substrate to reduce conductor losses experienced in wearable coils. Methods: A single channel coil was developed from a copper sheet using a cutting plotter. The coil was loaded onto a spherical phantom to evaluate the SNR when compared with standard rigid and flexible PCB based coils. A nine-channel wearable array was developed for structural and kinematic imaging of the shoulder at 3T. The SNR from the phantom and in vivo images was compared with a commercial flexible coil. Results: The single channel coil provided 2.1 times the SNR of the rigid PCB coil and 1.2 times the SNR of the flexible PCB coil. Image acquisition using the shoulder array can be accelerated twice or thrice in the left-right or superior-inferior directions. The shoulder array provided a 12.1% increase in SNR than the commercial array from phantom imaging. The wearable shoulder array provided an 10.5% increase in average SNR when compared to the commercial coil across 2D and 3D in vivo images. Clinical Impact: The application of copper traces directly on fabric provides a new outlook toward the development of wearable coils by eliminating inherent conductor losses to improve the image quality for musculoskeletal MRI.