title: Pathological alterations and stress responses near DBS electrodes after MRI scans at 7.0T, 3.0T and 1.5T: an in vivo comparative study.
abstract: OBJECTIVE
  The purpose of this study was to investigate the pathological alterations and the stress responses around deep brain stimulation (DBS) electrodes after magnetic resonance imaging (MRI) scans at 7.0T, 3.0T and 1.5T.
  
  
  METHODS
  DBS devices were stereotactically implanted into the brains of New Zealand rabbits, targeting the left nucleus ventralis posterior thalami, while on the right side, a puncture passage pointing to the same target was made. MRI scans at 7.0T, 3.0T and 1.5T were performed using transmit/receive head coils. The pathological alterations of the surrounding tissue were evaluated by hematoxylin and eosin staining (H&E staining) and transmission electron microscopy (TEM). The levels of the 70 kDa heat shock protein (HSP-70), Neuronal Nuclei (NeuN) and Caspase-3 were determined by western-blotting and quantitative polymerase chain reaction (QPCR) to assess the stress responses near the DBS electrodes.
  
  
  RESULTS
  H&E staining and TEM showed that the injury around the DBS electrodes was featured by a central puncture passage with gradually weakened injurious alterations. Comparisons of the injury across the groups manifested similar pathological alterations near the DBS electrodes in each group. Moreover, western-blotting and QPCR assay showed that the level of HSP-70 was not elevated by MRI scans (p>0.05), and the levels of NeuN and Caspase-3 were equal in each group, regardless of the field strengths applied (p>0.05).
  
  
  CONCLUSIONS
  Based on these findings, it is reasonable to conclude that in this study the MRI scans at multiple levels failed to induce additional tissue injury around the DBS electrodes. These preliminary data furthered our understanding of MRI-related DBS heating and encouraged revisions of the current MRI guidelines for patients with DBS devices.
authors.affiliation: Department of Functional Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Shi
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: An-Chao
authors.initials: AC
authors.lastname: Yang
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Meng
authors.affiliation: Department of Functional Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.
authors.forename: Shao-Wu
authors.initials: SW
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Huan-Guang
authors.initials: HG
authors.lastname: Liu
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; Department of Neurosurgery, People's Hospital of Hainan Province, Haikou, Hainan Province, China.
authors.forename: Jun-Ju
authors.initials: JJ
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Xiu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Functional Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Functional Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China; Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D053148:Caspase 3 / Q000032:analysis / Q000378:metabolism; D046690:Deep Brain Stimulation / Q000009:adverse effects* / Q000379:methods; D004567:Electrodes, Implanted / Q000009:adverse effects*; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000009:adverse effects* / Q000379:methods; D008297:Male; D011817:Rabbits; D013312:Stress, Physiological
chemical_list: D018840:HSP70 Heat-Shock Proteins; D053148:Caspase 3