The name is absent

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the same order of magnitude as the field in the bore of the scanner (the scanner used in
our research is a three tesla scanner) and significantly distorts it, thereby greatly
distorting the MRI image. Additionally the rapid pulses of the TMS also emit a high
amount of RF noise, drowning out the MRI signal. A TMS pulse therefore cannot be
given during acquisition of an image, and enough time must be given between image
acquisitions to give a TMS pulse. To accomplish this a clustered acquisition protocol
must be used, with the TR extended by 250ms (roughly the time needed to arm the
TMS, set the strength level, and trigger a pulse) during which time the scanner is
inactive.

Noise caused by the recharging capacitor bank

The TMS system uses a large bank of capacitors to build up enough charge to
produce the TMS pulse. After each pulse the capacitors have to recharge before
another pulse can be given. Since the coil is connected to the bank of capacitors, the
rising voltage of the capacitors creates a current through the coil. This current is
relatively small, however because of the large inductance of the TMS coil, its position
inside the bore of the scanner, and the extreme sensitivity of MRI scanner, it creates
more than enough noise to drown out any useful signal. To illustrate this we scanned a
phantom while delivering TMS pulses in between image acquisitions. We initially set
the strength of the pulse to 10% and gradually increased it after every image until the
maximum strength was reached. The resulting time series is shown in figure 6. As you

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