| 摘要 |
<p>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 1/4 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. Distortion of the uniform B field is avoided by twisting the conductors (78, 80) of the line and by winding the inductances in a bifilar winding mode.</p> |
