The invention relates to a radio-frequency coil (RF-coil) (19) for use in
a magnetic-resonance imaging apparatus. The RF-coil comprises a number of
parallel bar-shaped electric conductors (37), which are arranged at
regular intervals on an imaginary cylinder (39) and which are surrounded
by a radio-frequency shield (RF-shield) (49). The bar-shaped conductors
surround a measuring volume (11) of the device and are interconnected at
at least one of their end portions (41, 45) by means of an electric end
conductor (43, 47) extending in a plane transverse to the bar-shaped
conductors.
According to the invention, a further electric end conductor (51, 53) is
arranged near and parallel to the end conductor (43, 47), and said
further end conductor is electrically connected to the RF-shield (49),
preferably by means of a flange-shaped electric conductor (55, 57). The
end conductor (43, 47) and the further end conductor (51, 53) together
form an electrical transmission line. As a result, an unwanted
electromagnetic field (b.sub.1), which is generated by the current in the
end conductor (43, 47), is compensated for by an electromagnetic field
(b.sub.2) generated by the current in the further end conductor (51, 53).
Thus, the electromagnetic field of the end conductor (43, 47) does not
lead to unwanted dissipation effects and temperature increases in the
body of a patient present in the measuring volume (11).
