Length matters: Improved high field EEG–fMRI recordings using shorter EEG cables

Assecondi, Sara; Lavallee, Christina F.; Ferrari, P.; Jovicich, Jorge

doi:10.1016/j.jneumeth.2016.05.014

Cited by 15 publications

(20 citation statements)

References 48 publications

(56 reference statements)

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“…Assecondi et al also tested this phenomenon at 4T, observing a difference of 1.5 • C temperature increase between two cable lengths [89].…”

Section: Connection Cables (Leads) and Their Configurationmentioning

confidence: 97%

“…Other authors such as Bonmassar and colleagues investigated the effect of MR induced heating by the addition of junction field effect transistor (JFET) in a circuit connected to the scalp EEG has been determined to produce isolated currents with less noise when it is in OFF mode [71]. The safety profile of scalp EEG have been further characterized using similar protocols and a range of different MRI protocols and clinical setups [84,87,89,90,[99][100][101][102]. The summaries of the safety studies of scalp EEG in MRI are listed in Table 1.…”

Section: Survey Of the Experimental Literature On The Safety Of Scalpmentioning

confidence: 99%

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Safety of Simultaneous Scalp or Intracranial EEG during MRI: A Review

Hawsawi

Carmichael²,

Lemieux

2017

Front. Phys.

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Understanding the brain and its activity is one of the great challenges of modern science. Normal brain activity (cognitive processes, etc.) has been extensively studied using electroencephalography (EEG) since the 1930's, in the form of spontaneous fluctuations in rhythms, and patterns, and in a more experimentally-driven approach in the form of event-related potentials (ERPs) allowing us to relate scalp voltage waveforms to brain states and behavior. The use of EEG recorded during functional magnetic resonance imaging (EEG-fMRI) is a more recent development that has become an important tool in clinical neuroscience, for example for the study of epileptic activity. The purpose of this review is to explore the magnetic resonance imaging safety aspects specifically associated with the use of scalp EEG and other brain-implanted electrodes such as intracranial EEG electrodes when they are subjected to the MRI environment. We provide a theoretical overview of the mechanisms at play specifically associated with the presence of EEG equipment connected to the subject in the MR environment, and of the resulting health hazards. This is followed by a survey of the literature on the safety of scalp or invasive EEG-fMRI data acquisitions across field strengths, with emphasis on the practical implications for the safe application of the techniques; in particular, we attempt to summarize the findings in terms of acquisition protocols when possible.

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“…Assecondi et al also tested this phenomenon at 4T, observing a difference of 1.5 • C temperature increase between two cable lengths [89].…”

Section: Connection Cables (Leads) and Their Configurationmentioning

confidence: 97%

Section: Survey Of the Experimental Literature On The Safety Of Scalpmentioning

confidence: 99%

Safety of Simultaneous Scalp or Intracranial EEG during MRI: A Review

Hawsawi

Carmichael²,

Lemieux

2017

Front. Phys.

View full text Add to dashboard Cite

show abstract

“…The system also causes patient discomfort, prolongs preparation time, affects imaging quality, especially at a high field (7 Tesla or above) [30].…”

Section: Introductionmentioning

confidence: 99%

“…The longer stimulation cables sometime pick up fast gradient magnetic fields and lead to unwanted electrical stimulation [24][25]. Few studies include conditionally MRsafe stimulators placed near the MRI bore with shorter cables and RF filtering [26]-[28][29].However, such setups are difficult to scale up, since more stimulation channels would require more cables and RF filtering circuits and amount to an increasingly bulky and complex system.The system also causes patient discomfort, prolongs preparation time, affects imaging quality, especially at a high field (7 Tesla or above) [30].…”

mentioning

confidence: 99%

MRI Powered and Triggered Current Stimulator for Concurrent Stimulation and MRI

Mandal

Babaria²,

Cao

et al. 2019

Preprint

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Bioelectric stimulation during concurrent magnetic resonance imaging (MRI) is of interest to basic and translational studies. However, existing stimulation systems often interfere with MRI, are difficult to use or scale up, have limited efficacy, or cause safety concerns. To address these issues, we present a novel device capable of supplying current stimulation synchronized with MRI while being wirelessly powered by the MRI gradient fields. Results from testing it with phantoms and live animals in a 7 Tesla small-animal MRI system suggest that the device is able to harvest up to 72 (or 18) mW power during typical echo-planar imaging (or fast low angle shot imaging) and usable for stimulating peripheral muscle or nerve to modulate the brain or the gut, with minimal effects on MRI image quality. As a compact and standalone system, the plug-and-play device is suitable for animal research and merits further development for human applications. Introduction:Neurostimulation, e.g. Deep Brain Stimulation (DBS), Vagal Nerve Stimulation (VNS), Spinal Cord Stimulation (SCS), has been widely used to treat Parkinson's disease [1], dystonia [2], [3], epilepsy [4], [5], and intractable pain syndrome [6], [7], to name a few examples. It has also been increasingly recognized that magnetic resonance imaging (MRI) can guide neuromodulation and improve its efficacy, especially if neural stimulation and imaging are performed simultaneously [8]-[12]. However, concurrent stimulation and MRI is non-trivial. A conventional stimulation device may jeopardize patient safety and degrade imaging quality [13], while MRI may interfere with the device and corrupt its function [14]-[16], due to the strong and varying magnetic fields during MRI [17]. In addition, a device often requires long cables to connect to a power source or receive external triggers, where-as such cables may perturb the magnetic fields and degrade image acquisition [18], [19]. Widely used methods for simultaneous MRI and neuromodulation involve non-MR-safe stimulators, which are placed outside the MRI room and connected to the subject using long twisted cables [20]-[23]. The longer stimulation cables sometime pick up fast gradient magnetic fields and lead to unwanted electrical stimulation [24][25]. Few studies include conditionally MRsafe stimulators placed near the MRI bore with shorter cables and RF filtering [26]-[28][29].However, such setups are difficult to scale up, since more stimulation channels would require more cables and RF filtering circuits and amount to an increasingly bulky and complex system.The system also causes patient discomfort, prolongs preparation time, affects imaging quality, especially at a high field (7 Tesla or above) [30].

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“…MR-safety and compatibility are of paramount concern for any device working inside the MRI [12]- [14]. Apart from safety, the major bottleneck is the electromagnetic (EM) artifacts generated by (a) the static magnetic field, (b) strong RF deposition, and most importantly, (c) the rapidly changing gradient magnetic fields [6], [15]- [17]. These artifacts may be orders of magnitude larger than the signals of interest [15], [18]- [20].…”

Section: Introductionmentioning

confidence: 99%

Adaptive and Wireless Recordings of Electrophysiological Signals during Concurrent Magnetic Resonance Imaging

Mandal

Babaria

Cao

et al. 2018

Preprint

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Strong electromagnetic fields that occur during functional magnetic resonance imaging (fMRI) presents a challenging environment for concurrent electrophysiological recordings. Here, we present a miniaturized, wireless platform -"MR-Link" (Multimodal Recording Link) that provides a hardware solution for simultaneous electrophysiological and fMRI signal acquisition. The device detects the changes in the electromagnetic field during fMRI to synchronize amplification and sampling of electrophysiological signals with minimal artifacts. It wirelessly transmits the recorded data at a frequency detectable by the MR-receiver coil. The transmitted data is readily separable from MRI in the frequency domain. To demonstrate its efficacy, we used this device to record electrocardiograms and somatosensory evoked potential during concurrent fMRI scans. The device minimized the fMRI-induced artifacts in electrophysiological data and wirelessly transmitted the data back to the receiver coil without compromising fMRI signal quality. The device is compact (22 mm dia., 2gms) and can be placed within the MR-bore to precisely synchronize with fMRI. Therefore, MR-Link offers an inexpensive system by eliminating the need for amplifiers with a high dynamic range, high-speed sampling, additional storage or synchronization hardware for electrophysiological signal acquisition. It is expected to enable a broader range of applications of simultaneous fMRI and electrophysiology in animals and humans.

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Length matters: Improved high field EEG–fMRI recordings using shorter EEG cables

Cited by 15 publications

References 48 publications

Safety of Simultaneous Scalp or Intracranial EEG during MRI: A Review

Safety of Simultaneous Scalp or Intracranial EEG during MRI: A Review

MRI Powered and Triggered Current Stimulator for Concurrent Stimulation and MRI

Adaptive and Wireless Recordings of Electrophysiological Signals during Concurrent Magnetic Resonance Imaging

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