SHIMMING OF ELECTRIC FIELD FOR ELECTRIC PROPERTIES TOMOGRAPHY

摘要

A radio frequency coil system (34) used in the context of electric properties tomography (EPT, electrical impedance tomography, EIT, applied potential tomography, APT) generates radio frequency excitation pulses in an examination region (14). The radio frequency coil system (34) includes N coil elements (38) which generate magnetic (H) and electric (E) fields. A weight setting device (54) sets weight factors for input signals for the coil elements (38). A transmitting system (52) creates RF pulses, at least two sets of each with differently weighted input signals, and transmits the at least two sets of RF pulses to the coil elements (38) such that each of the transmitted RF pulse sets generates shifted electric fields (110, 112) having a shifted zero crossing point (120, 122) from each other. An image processor (62) computes electric permittivity maps from resonance induced by the at least two sets of RF pulses with different weighting.