title: Implantable RF-coil with multiple electrodes for long-term EEG-fMRI monitoring in rodents.
abstract: Simultaneous EEG-fMRI is a valuable tool in the clinic as it provides excellent temporal and spatial information about normal and diseased brain function. In pre-clinical research with small rodents, obtaining simultaneous EEG-fMRI in longitudinal studies faces a number of challenges, including issues related to magnetic susceptibility artifacts.
  
  
  
  Here, we demonstrate a method for permanent MRI RF-coil and EEG electrode implantation in rats that is suitable for long-term chronic follow-up studies in both stimulus and resting-state fMRI paradigms.
  
  
  
  Our findings showed that the screw-free implantation method is well suited for long-term follow-up studies in both freely moving video-EEG settings and fMRI without causing MRI susceptibility artifacts. Furthermore, the results demonstrated that a multimodal approach can be used to track the progression of structural and functional changes.
  
  
  
  The quality of both MRI and EEG data were comparable to those obtained with traditional methods with the benefit of combining them into artifact-free simultaneous recordings. The signal-to-noise ratios of the MRI images obtained with the implanted RF-coil were similar to those using a quadrature coil and were therefore suitable for resting-state fMRI experiments. Similarly, EEG data collected with the RF-coil/electrode set-up were comparable to EEG recorded with traditional epidural screw electrodes.
  
  
  
  This new multimodal EEG-fMRI approach provides a novel tool for concomitant analysis and follow-up of anatomic and functional MRI, as well as electrographic changes in a preclinical research.
authors: Department of Neurobiology, A.I. Virtanen Institute for Molecular Medicine, University of Eastern Finland, 70211, Kuopio, Finland. Electronic address: tiina.pirttimaki@uef.fi.
authors: Tiina
authors: T
authors: Pirttimäki
authors: Department of Neurobiology, A.I. Virtanen Institute for Molecular Medicine, University of Eastern Finland, 70211, Kuopio, Finland.
authors: Raimo A
authors: RA
authors: Salo
authors: Department of Neurobiology, A.I. Virtanen Institute for Molecular Medicine, University of Eastern Finland, 70211, Kuopio, Finland.
authors: Artem
authors: A
authors: Shatillo
authors: Department of Neurobiology, A.I. Virtanen Institute for Molecular Medicine, University of Eastern Finland, 70211, Kuopio, Finland.
authors: Mikko I
authors: MI
authors: Kettunen
authors: Department of Neurobiology, A.I. Virtanen Institute for Molecular Medicine, University of Eastern Finland, 70211, Kuopio, Finland.
authors: Jaakko
authors: J
authors: Paasonen
authors: Department of Neurobiology, A.I. Virtanen Institute for Molecular Medicine, University of Eastern Finland, 70211, Kuopio, Finland.
authors: Alejandra
authors: A
authors: Sierra
authors: Department of Neurobiology, A.I. Virtanen Institute for Molecular Medicine, University of Eastern Finland, 70211, Kuopio, Finland.
authors: Kimmo
authors: K
authors: Jokivarsi
authors: Institute of Clinical Medicine - Neurosurgery, University of Eastern Finland and Neurosurgery of NeuroCenter, Kuopio University Hospital, 70029, Kuopio, Finland.
authors: Ville
authors: V
authors: Leinonen
authors: Department of Neurobiology, A.I. Virtanen Institute for Molecular Medicine, University of Eastern Finland, 70211, Kuopio, Finland.
authors: Pedro
authors: P
authors: Andrade
authors: RAPID Biomedical GmbH, 97222, Rimpar, Germany.
authors: Simon
authors: S
authors: Quittek
authors: Department of Neurobiology, A.I. Virtanen Institute for Molecular Medicine, University of Eastern Finland, 70211, Kuopio, Finland.
authors: Asla
authors: A
authors: Pitkänen
authors: Department of Neurobiology, A.I. Virtanen Institute for Molecular Medicine, University of Eastern Finland, 70211, Kuopio, Finland. Electronic address: olli.grohn@uef.fi.
authors: Olli
authors: O
authors: Gröhn
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000503:physiopathology*; D001930:Brain Injuries / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000503:physiopathology; D001931:Brain Mapping; D004567:Electrodes, Implanted; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects / Q000502:physiology; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity; D005500:Follow-Up Studies; D007091:Image Processing, Computer-Assisted; D007608:Kainic Acid / Q000633:toxicity; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008991:Monitoring, Physiologic; D010100:Oxygen / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D059629:Signal-To-Noise Ratio
chemical_list: D018690:Excitatory Amino Acid Agonists; D010100:Oxygen; D007608:Kainic Acid
keywords: BOLD; Chronic implant; EEG; Rat; Resting state; fMRI