title: The role of intraoperative magnetic resonance imaging for the detection of hemorrhagic complications during surgery for intracerebral lesions an experimental approach.
abstract: BACKGROUND
  Intraoperative magnetic resonance imaging (MRI) for guided biopsy or microsurgical resection of intracranial lesions is gaining broader acceptance. It is not known whether intraoperative MRI has the potential to detect hemorrhagic complications of these surgical procedures, because scientific research has so far focussed on the signal characteristics of less acute clots. It is the objective of this experimental study to investigate whether MRI can visualise intracerebral blood within minutes after its occurrence.
  
  
  METHODS
  In 26 pigs, a frontal hematoma was produced by injecting autologous blood. Twenty pigs underwent MRI 30 minutes after injection, and 6 pigs within the first 10 minutes. MRI scans were performed on a 1.5T system. T1-weighted spin echo (SE), T2-weighted turbo spin echo (TSE), T2-weighted fluid attenuated inversion recovery (FLAIR), and T2-weighted gradient echo (GE) images were acquired. Depending on the differences of the signal intensities of the hematoma and the surrounding brain, the detectability of the hematoma was rated as good, fair, or poor.
  
  
  RESULTS
  None of the induced hematomas were rated to be clearly visible on T1-weighted sequences. Six of the 26 hematomas (23%) were easily detectable on FLAIR sequences, 18 hematomas (69%) on T2-weighted TSE sequences, and 23 hematomas (88%) on the T2-weighted GE sequences.
  
  
  CONCLUSIONS
  Extravasated blood can be identified with a high reliability within minutes after its occurrence on MRI provided that T2-weighted GE sequences are used for imaging. In conclusion, intraoperative MRI is not only of value for guidance of neurosurgical procedures, but also for immediate detection of hemorrhagic complications.
authors.affiliation: Department of Neurosurgery, Aachen University of Technology (RWTH), Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Rohde
authors.forename: I
authors.initials: I
authors.lastname: Rohde
authors.forename: R
authors.initials: R
authors.lastname: Thiex
authors.forename: W
authors.initials: W
authors.lastname: Küker
authors.forename: A
authors.initials: A
authors.lastname: Ince
authors.forename: J M
authors.initials: JM
authors.lastname: Gilsbach
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology; D001927:Brain Diseases / Q000601:surgery*; D002543:Cerebral Hemorrhage / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D006406:Hematoma / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D007431:Intraoperative Complications / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D019635:Neurosurgical Procedures / Q000009:adverse effects; D013552:Swine; D013997:Time Factors