Physical Setup and Testing
The headstage cable should be aligned with the center of the bore and extend straight out
from the isocenter of the magnet. Make sure the headstage cable is long enough for this.
The ampli
fi
er may generate artifacts on the scan if inside the MRI room. Set the ampli
fi
er as far
away from the scanner as possible. Placing it outside the 5 gauss line is best, if possible.
Leaving the ampli
fi
er in a strong magnetic
fi
eld will either cause the batteries to fail or shorten
the battery life of the ampli
fi
er.
Penetration Panel
The scanner room is well-shielded against radio frequency (RF) noise that affects the image
quality. The headstage cable passes from the scanner room to the control room through a
penetration panel that may contain RF
fi
lters and waveguides.
Penetration panels limit the high frequency signals emitted by the PZ5 / PZA Subject Interface
amp. They do not resolve RF noise that is generated along the cable from the PZ5 / PZA
Subject Interface amp to the MRI. Any additional RF noise can be
fi
ltered with the passive low-
pass 50MHz RF
fi
lter that comes with the TDT MRI-KIT. The RF
fi
lter is placed in-line between
the ampli
fi
er and headstage. All wires (recording channels, subject ground, and reference)
pass through this
fi
lter. This has to be grounded properly to work*. It has standard 1.5 mm DIN
(touch-proof) connectors to connect to the ground on the scanner itself. This then connects to
the RZ processor for real-time scanner artifact removal.
Connectors on the PZ5 / PZA Subject Interface are ferrous and will be attracted to the magnet. Use extreme
caution when handling the ampli
fi
er anywhere near the magnet. In general the PZ5 / PZA Subject Interface is
heavy enough it won't be pulled into the bore, but it should remain outside the 5 gauss line if possible.
Danger
*The RF
fi
lter ground is different than the subject ground.
Important
fMRI User Guide | 21
