Magnetic resonance imaging apparatus including a bird-cage r.f. coil

摘要

Disclosed is a magnetic resonance imaging apparatus, with an r.f. coil which is designed on the basis of the sinusoidal current distribution across a circular-cylindrical surface about a central coil axis and which is, subject to a generally applicable looping-through condition z1=-K z2, when K is a positive constant which depends on the number of bars and geometrical deviations, z1 is the impedance of the bar conductors, and z2 is the impedance of ring conductor elements between each two pair of bar conductors. The coil based on the above condition is particularly adapted to parasitic capacitances of the bar conductors and to the general shape of objects to be examined.