An intracavity probe for use with an MR system allows images and spectra of internal anatomical structures to be obtained. The intracavity probe houses within its balloon-type enclosure a single-element quadrature coil sensitive to both the vertical and horizontal components of the MR signal. The quadrature coil by means of its output line is designed to plug into a dedicated interface device with which to interface the quadrature coil with the MR system. Drive capacitors within the coil in conjunction with the electrical length of the output line and phase shifting networks within the interface device enable complete decoupling of the quadrature coil from the transmit fields generated by the MR system. Preamplifier, power splitting and combining networks within the interface device process voltage signals representative of the horizontal and vertical components of the MR signal and enable them to be conveyed to the input port(s) of the MR system.