Abstract: In a medical MRI apparatus, it is often desirable to have devices 62, 64 for communicating with or monitoring the patient 58 in the imaging volume 29 of the apparatus. Such devices need DC power or low-frequency connections with an area 70 outside the imaging volume. A device cable that does not interfere with the MRI magnetic fields is known per se. The invention proposes to fix the device cable in a groove 76 in the patient carrier 60 in such a manner that its strip-shaped conductors 78, 80 extend parallel to the field lines of the stationary field B of the apparatus. In this way, it is also possible to clip device carriers 72, 74 to the groove, thus supplying the devices with DC power or establishing an audio connection through the device cable in the groove.

Abstract: An invasive device 17, such as a catheter, is connected to a supply and control unit via a connection conductor 21 for the transfer of power supply energy and/or LF signals to and from an electrical circuit 20 in the distal part 18 of the device. During operation the connection conductor traverses the homogeneous magnetic field and the RF field of the MRI apparatus; this may give rise to heating of the connection conductor and/or to a disturbance of said fields. In order to mitigate these drawbacks, the connection conductor in accordance with the invention is subdivided into mutually separated segments 22-i, each of which is much shorter (for example, 1/20) than the wavelength of the RE field in the apparatus; the segments are separated from one another by separating elements 23-i (self-inductances) that provide a high inductance for said RF frequencies and a low inductance for comparatively low frequencies.

Abstract: In medical MRI apparatus it is often desirable to maintain a connection with the patient 58 to be examined, for example in order to observe the patient by means of a television camera 62 or to monitor physical functions like the heart rate or blood pressure. It is often necessary to use electrically powered connection equipment 62, 64 which is located in or very close to the imaging area 29, the supply lines 66, 68 also being located in the imaging area so that the (precisely defined) fields required for imaging would be disturbed thereby. According to the invention the supply lines are subdivided into segments 72-i, each of which has a length shorter than ¼ of the wavelength of the RF field; these segments are separated from one another by inductances 74-i. Consequently, the supply line does not present itself as an energy absorbing conductor to the RF field, so that the RF field is not disturbed thereby.

Abstract: An invasive device 17, such as a catheter, is connected to a supply and control unit via a connection conductor 21 for the transfer of power supply energy and/or LF signals to and from an electrical circuit 20 in the distal part 18 of the device. During operation the connection conductor traverses the homogeneous magnetic field and the RF field of the MRI apparatus; this may give rise to heating of the connection conductor and/or to a disturbance of said fields. In order to mitigate these drawbacks, the connection conductor in accordance with the invention is subdivided into mutually separated segments 22-i, each of which is much shorter (for example, 1/20) than the wavelength of the RF field in the apparatus; the segments are separated from one another by separating elements 23-i (self-inductances) that provide a high inductance for said RF frequencies and a low inductance for comparatively low frequencies.