(3) Will there be significant forces on the leg and end ring conductors while doing TMS? Would this preclude using adhesive backed copper strips for the conductors?
(4) How should the leg conductors be fabricated? Will we need to consider supporting the TMS coil using the nested BC support structures?
(5) Are there any special considerations to be made with respect to the support material? In particular what about heat resistance? Do we have higher likelihood of heating or arcing when combined with TMS? There was a TMS melt down incident a few months ago.
(6) Does TMS coil position produce BC asymmetries (stray capacitance) and therefore frequency shifts and degeneracy breaking of the sin and cos modes for a particular frequency? Will this cause problems if quadrature detection is used? Should we use quadrature detection? Would it be a good idea to have variable capacitors that could be adjusted by us to compensate the presence of the TMS coil or is that nuts?
(6) Apparently the hybrid BC is less sensitive to loading-related frequency shifts ("Birdcage Volume Coil Design" by De Zanche 2011) than low or high pass BCs. Should we go with a hybrid coil the?
(7) What are the options for coupling the nested birdcage elements to the receiver amps? Is inductive coupling a bad idea?
(8) If we don't go with a hybrid coil then would high pass or low pass be best? Would one induce less eddy currents and losses in the TMS coil due to the orientation of the respective E fields?
(9) Could the TMS pulse bias the switching diodes in the coil and thereby change the switch off time for the diodes?
(10) Are we inducing circuit currents in the birdcage when we pulse the TMS or are we inducing eddy currents only?
(11) Is there a SNR cost associated with using preamp decoupling of the nest elements?
(12) Can we shield the birdcage (as well as the gradient coils) from the TMS pulses?
Nested Birdcage (BC) Questions
(1) What diameter for the BCs?
(2) How many legs?
(3) Will there be significant forces on the leg and end ring conductors while doing TMS? Would this preclude using adhesive backed copper strips for the conductors?
(4) How should the leg conductors be fabricated? Will we need to consider supporting the TMS coil using the nested BC support structures?
(5) Are there any special considerations to be made with respect to the support material? In particular what about heat resistance? Do we have higher likelihood of heating or arcing when combined with TMS? There was a TMS melt down incident a few months ago.
(6) Does TMS coil position produce BC asymmetries (stray capacitance) and therefore frequency shifts and degeneracy breaking of the sin and cos modes for a particular frequency? Will this cause problems if quadrature detection is used? Should we use quadrature detection? Would it be a good idea to have variable capacitors that could be adjusted by us to compensate the presence of the TMS coil or is that nuts?
(6) Apparently the hybrid BC is less sensitive to loading-related frequency shifts ("Birdcage Volume Coil Design" by De Zanche 2011) than low or high pass BCs. Should we go with a hybrid coil the?
(7) What are the options for coupling the nested birdcage elements to the receiver amps? Is inductive coupling a bad idea?
(8) If we don't go with a hybrid coil then would high pass or low pass be best? Would one induce less eddy currents and losses in the TMS coil due to the orientation of the respective E fields?
(9) Could the TMS pulse bias the switching diodes in the coil and thereby change the switch off time for the diodes?
(10) Are we inducing circuit currents in the birdcage when we pulse the TMS or are we inducing eddy currents only?
(11) Is there a SNR cost associated with using preamp decoupling of the nest elements?
(12) Can we shield the birdcage (as well as the gradient coils) from the TMS pulses?