MagVenture's solution for interleaved TMS/fMRI in 1.5-4.0T scanners effectively addresses the associated problems with static and dynamic artifacts. It also addresses the inherent safety aspects.

Minimized Artifacts

Smart sensors limit unsafe pulse configurations and temperature increases.
The mere presence of the coil can create artifacts. In order to minimize eddy current effects, individually isolated copper litze wires are used in the MRi-B91 coil. To minimize coil vibrations, which also cause artifacts, the mechanical damping properties of the coil have been optimized. To ease installation in MR-compatible coil holders, the MRi-B91 comes with two holes at the center of the two windings.

Reduced RF Noise

The Power line filter provides high image quality and allows equipment to be used in scanners from 1.5-4.00 Tesla.
RF noise can greatly affect the signal-to-noise ratio. To effectively prevent RF noise being brought into the scanner room from the MagPro stimulator, a Power Line Filter mounted on the outside of the scanner wall, filters power and signal cables. The power line filters reduce 40MHz to 200MHz RF noise by 99.99%, which allows use in scanners in the 1.5T (RF 64MHz) to 4.0T (RF 170MHz) range.

Balanced Leakage Current

Eliminates leakage currents through internal circuits. 
To reduce Leakage Current in the coil while the MagPro is not stimulating, the MagPro stimulators for TMS/fMRI are modified so that a reverse current is sent into the output connector with reverse "polarity" and proportional to the intensity.

Stimulator Recharge Delay

Prevents unwanted noised generated when stimulator recharges until acquisition of images is completed. 
The noise generated when the MagPro stimulator recharges can interfere with the image quality. The Charge Delay functionality in the TMS/fMRI solution from MagVenture can inhibit this noise. The charge delay can be adjusted from 0 ms to 12.000 ms.

Increased Safety

Smart sensors limit unsafe pulse configurations and temperature increases.
Safety aspects are dealt with effectively. Due to the static magnetic field of the scanner, the MRi-B91 coil can only withstand standard biphasic pulses and for this reason the MagPro stimulators are automatically locked in biphasic pulse mode when the MRi-B91 is attached. Coil, Remote Control and Emergency Stop contain no ferromagnetic materials and two emergency stops can be connected - one for the patient/volunteer; one for scanner personnel.