Simultaneous reception from a whole-volume coil and a surface coil on a clinical MR system

Simultaneous acquisition of signals from the same anatomic region with use of both the head or body coil and a surface coil was demonstrated on healthy volunteers with a commercial magnetic resonance imaging system and a hybrid combiner. An improvement in the signal-to-noise ratio (S/N) over that which is obtained with the surface coil alone was demonstrated at depths of 3-4 cm and greater from the surface of the body. The practical necessity of use of the hybrid combiner to add the signals created several problems, such as the inability to obtain the predicted increase in S/N in certain areas and an actual decrease in S/N close to the surface coil. These problems would have been avoided with the use of two separate data channels. The only problem intrinsic to the method is a "wraparound" of structures and motion artifacts onto the field of view.