According to one aspect, a magnetic resonance imaging (MRI) scanner includes a short birdcage (e.g. millipede) distributed-capacitance radio-frequency (RF) coil formed from one or more patterned planar conductive foils. The transverse extent (e.g. diameter) of the coil is at least a factor of 3, for example about a factor of 10, larger than the longitudinal (z-axis) extent of the coil. Flux-return gaps may be provided between the sample measurement volume defined by the coil and RF shields adjacent to the sample measurement volume, to confine the RF magnetic field to the sample measurement volume. Exemplary coils described herein are particularly suited for very high-frequency MRI measurements.