Abstract: A circuit for detuning a resonator in a nuclear magnetic resonance imaging apparatus has an output connected to a terminal of the resonator via a high-frequency line composed of two conductors. The resonator is shortened at this terminal with a shorting capacitor that can be short-circuited for detuning the resonator. The length of the high-frequency line is shorter than one-fourth of the wavelength of a high-frequency signal having the operating frequency of the nuclear magnetic resonance imaging apparatus on the high-frequency line. For detuning the resonator the high-frequency line can be terminated at the output with a further capacitor, so that the high-frequency line acts as a short-circuit at the terminal.

Abstract: A cable guide for use in a nuclear magnetic resonance tomography apparatus is provided for cable for making electrical connections between devices secured to a patient bed and devices disposed outside of the examination space. The cable guide is a grounded, electrical cable channel disposed beneath the patient bed and above the lower sub-antenna of a whole-body antenna and above at least one wall of the examination space. The cable channel has a V-shape, and is rounded at an edge facing the examination space, this edge projecting beyond the height of the lower sub-antenna. The cable guide substantially protects the cable against coupling with other components. The examination space remains free of built-in units.