The possibility to reduce implant
heating is an added value option of parallel transmission. An orthogonal-projection
method (OPM) is presented to reduce the E fields at the tip of wire type
implants by using voltage vectors orthogonal to the vector inducing the worst
case RF current at the protruding end of the implant. Experiments confirm that
the minimization of RF current at the protruding end leads to a distinct
reduction of the electric field at the tip of the wire. Low-hazard steering
conditions for n-element pTx coils
can be determined in real time during an MR investigation from the measurement
of only n complex valued RF currents
at the protruding end of the implant.
