title: Clinical evaluation and follow-up results for intraoperative magnetic resonance imaging in neurosurgery.
abstract: OBJECTIVE
  The use of intraoperative magnetic resonance imaging (MRI) in neurosurgery has increased rapidly, and a variety of concepts have recently been presented. Although the feasibility of the procedure has been demonstrated repeatedly, no conclusive analysis of its effects on the surgical procedures, the extent of tumor removal, and outcomes, or its possible problems, has been performed.
  
  
  METHODS
  Of 242 operations performed with intraoperative MRI, 97 procedures for supratentorial glioma treatment were analyzed with respect to intraoperative imaging results and postoperative outcomes. Analysis of the images included assessment of imaging artifacts, image quality, and extent of tumor removal. Patients were monitored to determine radiological progression, survival times, postoperative complications, and morbidity rates.
  
  
  RESULTS
  No intraoperative complications related to the imaging procedure were observed. Image quality was good or fair in 85.5% of the cases. Different types of surgically induced imaging changes could be identified. In 56 cases, resection was continued using navigation with intraoperative MRI data sets (rereferencing accuracy, 0.9 mm). For high-grade gliomas, the percentage of cases in which residual tumor was identified by MRI could be significantly reduced from 62% intraoperatively to 33% postoperatively, which was paralleled by a significant increase in survival times for patients without residual tumor. Complication and morbidity rates were within the ranges reported for other studies.
  
  
  CONCLUSIONS
  Intraoperative MRI is safe and allows reliable updating of neuronavigational data, with compensation for brain shifting. Surgically induced imaging changes, which have been identified as a possible problem with intraoperative MRI in general, necessitated comparisons with preoperative scans and require future attention. The extent of tumor removal and survival times were increased significantly. Overall, patients seemed to benefit from the method.
authors.affiliation: Department of Neurosurgery, University Hospital, Ruprecht-Karls-University Heidelberg, Germany. rainer_wirtz@med.uni-heidelberg.de
authors.forename: C R
authors.initials: CR
authors.lastname: Wirtz
authors.forename: M
authors.initials: M
authors.lastname: Knauth
authors.forename: A
authors.initials: A
authors.lastname: Staubert
authors.forename: M M
authors.initials: MM
authors.lastname: Bonsanto
authors.forename: K
authors.initials: K
authors.lastname: Sartor
authors.forename: S
authors.initials: S
authors.lastname: Kunze
authors.forename: V M
authors.initials: VM
authors.lastname: Tronnier
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000401:mortality / Q000601:surgery; D018365:Neoplasm, Residual / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D011183:Postoperative Complications / Q000175:diagnosis / Q000401:mortality; D015173:Supratentorial Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D015996:Survival Rate; D016896:Treatment Outcome