The patented* MagLink system is used for obtaining integrated EEG and ERP recordings inside the fMRI. This second-generation system improves on the original Opti-Link system by increasing the bandwidth and eliminating the pre-amplifier and optical coupling. The passive MagLink system provides the ability to record during the pulse sequence without compromising the raw EEG data. MagLink, in conjunction with Neuroscan amplifiers has successfully recorded EEG data through the pulse sequence in up to 3 Tesla MRI scanners. The CURRY 7 Acquisition and Signal Processing modules provide powerful features for on-line and off-line reduction of the ballistocardiogram and pulse sequence artifact, while retaining the integrity of the EEG. Post-processing tools allow ERP's to be extracted, which can then be subjected to source localization and compared with the fMRI.
The gradient artifact that is injected into the EEG data can be reduced by a number of different strategies that are included in the CURRY 7 software. Having a variety of data processing methods available is critical to account for the different artifacts that are encountered. The individual artifact signatures vary based on the type of pulse sequence, magnet type and strength, the electrode impedance, even the quality of the shim on a particular day. Neuroscan's correction methods can correct the EEG data under a variety of parameters.
The most recent development affecting gradient artifact reduction derives from the ability to synchronize the clocks between the amplifiers and the MRI Scanner. Clock synchronization improves the accuracy of gradient artifact reduction, simplifies the artifact reduction process and allows acquisition using standard sampling rates (e.g., 500 Hz).
The complete MagLink system consists of MagLink Cables, MagLink Caps, a Neuroscan amplifier and the CURRY 7 software. This fully functional system has acquired EEG and fMRI data successful in the following magnets:
GE Signa 1.5 Tesla
GE Signa 3.0 Tesla
Siemens 1.5 Tesla
Siemens 3.0 Tesla
Philips 1.5 Tesla
Specifications:
* U.S. Patent 6,708,051 B1: Filed 11/10/99, Issued: 16/03/04
* U.S. Patent 5,445,162 C1: Filed 08/27/93, Issued: 08/29/95, Recertification Issued 11/30/04
For more details, please refer to the MagLink brochure.
NOTE: MagLink RT is currently for investigational use only.