  Anatomy-specific RF receive coil arrays routinely adopted in magnetic
resonance imaging (MRI) for signal acquisition, are commonly burdened by their
bulky, fixed, and rigid configurations, which may impose patient discomfort,
bothersome positioning, and suboptimal sensitivity in certain situations.
Herein, leveraging coaxial cables' inherent flexibility and electric field
confining property, for the first time, we present wireless, ultra-lightweight,
coaxially-shielded MRI coils achieving a signal-to-noise ratio (SNR) comparable
to or surpassing that of commercially available cutting-edge receive coil
arrays with the potential for improved patient comfort, ease of implementation,
and significantly reduced costs. The proposed coils demonstrate versatility by
functioning both independently in form-fitting configurations, closely adapting
to relatively small anatomical sites, and collectively by inductively coupling
together as metamaterials, allowing for extension of the field-of-view of their
coverage to encompass larger anatomical regions without compromising coil
sensitivity. The wireless, coaxially-shielded MRI coils reported herein pave
the way toward next generation MRI coils.
