to the rf penetration artifact which is observed in conducting objects imaged at high frequencies the distortions are complementary to each other leading to an effective self compensation of the artifact when the coil is operated in quadrature as can be seen from the symmetrical b 1 pattern of the quadrature mode presented in fig3 c fig4 shows gradient echo images collected with the half volume tem coil operating in the transmit receive mode and the full volume transmit receive tem coil the images were collected to compare the sensitivities of the devices in addition images collected with the surface and the butterfly modes of the half volume tem coil are provided to illustrate the rf penetration artifact which distorts the images as in the case of the b 1 maps there are u201c hot u201d and u201c cold u201d spots in the linear surface and butterfly mode images that are complimentary to each other consequentially the artifact is suppressed when the modes are combined during quadrature operation of the coil it should be noted that the u201c hot u201d and u201c cold u201d spots in the images and the b 1 maps taken with either linear mode do not coincide but are rather formed on the opposite sides this relates to the fact that while the b 1 maps follow transmission profiles of the devices the images collected at high flip angles correspond to the receive profiles the sensitivity levels given in fig4 are normalized to the maximum level for the volume tem coil to further illustrate the sensitivity differences of the three devices the central slice profiles through the images are plotted in fig5 the plots represent the sensitivities as a function of the distance from the coils with the origin places at the edge.