title: Intraoperative magnetic resonance imaging findings during deep brain stimulation surgery.
abstract: OBJECTIVE
  Deep brain stimulation (DBS) is an established neurosurgical technique used to treat a variety of neurological disorders, including Parkinson disease, essential tremor, dystonia, epilepsy, depression, and obsessive-compulsive disorder. This study reports on the use of intraoperative MR imaging during DBS surgery to evaluate acute hemorrhage, intracranial air, brain shift, and accuracy of lead placement.
  
  
  METHODS
  During a 46-month period, 143 patients underwent 152 DBS surgeries including 289 lead placements utilizing intraoperative 1.5-T MR imaging. Imaging was supervised by an MR imaging physicist to maintain the specific absorption rate below the required level of 0.1 W/kg and always included T1 magnetization-prepared rapid gradient echo and T2* gradient echo sequences with selected use of T2 fluid attenuated inversion recovery (FLAIR) and T2 fast spin echo (FSE). Retrospective review of the intraoperative MR imaging examinations was performed to quantify the amount of hemorrhage and the amount of air introduced during the DBS surgery.
  
  
  RESULTS
  Intraoperative MR imaging revealed 5 subdural hematomas, 3 subarachnoid hemorrhages, and 1 intraparenchymal hemorrhage in 9 of the 143 patients. Only 1 patient experiencing a subarachnoid hemorrhage developed clinically apparent symptoms, which included transient severe headache and mild confusion. Brain shift due to intracranial air was identified in 144 separate instances.
  
  
  CONCLUSIONS
  Intraoperative MR imaging can be safely performed and may assist in demonstrating acute changes involving intracranial hemorrhage and air during DBS surgery. These findings are rarely clinically significant and typically resolve prior to follow-up imaging. Selective use of T2 FLAIR and T2 FSE imaging can confirm the presence of hemorrhage or air and preclude the need for CT examinations.
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Olivia O
authors.initials: OO
authors.lastname: Huston
authors.forename: Robert E
authors.initials: RE
authors.lastname: Watson
authors.forename: Matt A
authors.initials: MA
authors.lastname: Bernstein
authors.forename: Kiaran P
authors.initials: KP
authors.lastname: McGee
authors.forename: S Matt
authors.initials: SM
authors.lastname: Stead
authors.forename: Debb A
authors.initials: DA
authors.lastname: Gorman
authors.forename: Kendall H
authors.initials: KH
authors.lastname: Lee
authors.forename: John
authors.initials: J
authors.lastname: Huston
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology* / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D046690:Deep Brain Stimulation; D004567:Electrodes, Implanted; D005260:Female; D006408:Hematoma, Subdural / Q000473:pathology; D006801:Humans; D007432:Intraoperative Period; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000473:pathology