The present invention provides a safety monitoring device (10) for detecting radio frequency resonances in a subject of interest (12) comprising an essentially tubular examination space (14), which is vertically arranged, for locating therein the subject of interest (12), an radio frequency resonance device (16), which has at least one connection port (21), for covering at least a part of the examination space (14) along its longitudinal axis, a rotation device (22) for rotating the radio frequency resonance device (16) relative to the subject of interest (12), a controlling device (30) for controlling the rotation of the radio frequency resonance device (16), and a detection device (34) for monitoring an impedance of the at least one connection port (21) of the radio frequency resonance device (16) during the rotation and detecting radio frequency resonances out of the monitored impedance of the at least one connection port (21) of the radio frequency resonance device (16). The present invention further provides a method for detecting radio frequency resonances in a subject of interest (12) comprising the steps of locating the subject of interest (12) within an essentially tubular examination space (14), which is vertically arranged, rotating a radio frequency resonance device (16), which has at least one connection port (21), relative to at least a part of the examination space (14) along its longitudinal axis, monitoring an impedance of the at least one connection port (21) of the radio frequency resonance device during (16) the rotation, and detecting radio frequency resonances out of the monitored impedance of the at least one connection port (21) of the radio frequency resonance device (16).
