Frank
Seifert1,2, Tomasz Dawid Lindel1,2, Andr Kuehne1,2,
Helmar Waiczies1,2, Wolfgang Renz, 23, Bernd Ittermann1,2
1Physikalisch-Technische Bundesanstalt
(PTB), Abbestr. 2-12, D-10587 Berlin, Germany; 2Berlin
Ultrahigh Field Facility, Max-Delbrck-Center for Molecular Medicine, D-13125
Berlin, Germany; 3Siemens Healthcare, D-91052 Erlangen, Germany
Tx-SENSE
performance depends crucially on the reliable knowledge of the transmit
sensitivity maps of the coil elements. For 7T body imaging the virtual
reference approach fails to get reliable maps. This was shown for a simulated
Tx-SENSE based zoomed cardiac imaging experiment at 7T. FDTD simulations were
performed for a experimental 4-channel TX/RX coil array. Using either the
virtual reference approach or the true sensitivity maps two sets of RF pulse
shapes were calculated for a box like excitation pattern covering the heart.
For both RF pulse sets the flip angle distribution was calculated from a full
Bloch Equation simulation.
Keywords