Udskriv Udskriv
Switch language
Region Hovedstaden - en del af Københavns Universitetshospital

Safety and EEG data quality of concurrent high-density EEG and high-speed fMRI at 3 Tesla

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  1. Diagnostic added value of electrical source imaging in presurgical evaluation of patients with epilepsy: A prospective study

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  2. Inhibition of epileptiform activity by neuropeptide Y in brain tissue from drug-resistant temporal lobe epilepsy patients

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  3. Diagnostic yield of high-density versus low-density EEG: The effect of spatial sampling, timing and duration of recording

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  4. Dynamic soft tissue changes in the orbit after a blowout fracture

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  5. Effect of pituitary adenylate cyclase-activating polypeptide-27 on cerebral hemodynamics in healthy volunteers: A 3T MRI study

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Vis graf over relationer

PURPOSE: Concurrent EEG and fMRI is increasingly used to characterize the spatial-temporal dynamics of brain activity. However, most studies to date have been limited to conventional echo-planar imaging (EPI). There is considerable interest in integrating recently developed high-speed fMRI methods with high-density EEG to increase temporal resolution and sensitivity for task-based and resting state fMRI, and for detecting interictal spikes in epilepsy. In the present study using concurrent high-density EEG and recently developed high-speed fMRI methods, we investigate safety of radiofrequency (RF) related heating, the effect of EEG on cortical signal-to-noise ratio (SNR) in fMRI, and assess EEG data quality.

MATERIALS AND METHODS: The study compared EPI, multi-echo EPI, multi-band EPI and multi-slab echo-volumar imaging pulse sequences, using clinical 3 Tesla MR scanners from two different vendors that were equipped with 64- and 256-channel MR-compatible EEG systems, respectively, and receive only array head coils. Data were collected in 11 healthy controls (3 males, age range 18-70 years) and 13 patients with epilepsy (8 males, age range 21-67 years). Three of the healthy controls were scanned with the 256-channel EEG system, the other subjects were scanned with the 64-channel EEG system. Scalp surface temperature, SNR in occipital cortex and head movement were measured with and without the EEG cap. The degree of artifacts and the ability to identify background activity was assessed by visual analysis by a trained expert in the 64 channel EEG data (7 healthy controls, 13 patients).

RESULTS: RF induced heating at the surface of the EEG electrodes during a 30-minute scan period with stable temperature prior to scanning did not exceed 1.0° C with either EEG system and any of the pulse sequences used in this study. There was no significant decrease in cortical SNR due to the presence of the EEG cap (p > 0.05). No significant differences in the visually analyzed EEG data quality were found between EEG recorded during high-speed fMRI and during conventional EPI (p = 0.78). Residual ballistocardiographic artifacts resulted in 58% of EEG data being rated as poor quality.

CONCLUSION: This study demonstrates that high-density EEG can be safely implemented in conjunction with high-speed fMRI and that high-speed fMRI does not adversely affect EEG data quality. However, the deterioration of the EEG quality due to residual ballistocardiographic artifacts remains a significant constraint for routine clinical applications of concurrent EEG-fMRI.

TidsskriftP L o S One
Udgave nummer5
Sider (fra-til)e0178409
StatusUdgivet - 2017

ID: 51536519