title: Spatial distortion due to field inhomogeneity in 3.0 tesla intraoperative MRI.
abstract: We describe a 14-year-old boy with a pilocytic astrocytoma of the left caudate head. Preoperative localization MR imaging (MRI) was performed in the operating room, and spatial distortion was noted felt to be related to head positioning relative to the isocenter of the magnetic field. The distortion artifact was subtle enough to be difficult to detect, but large enough to change the location of the lesion potentially leading to a non-diagnostic stereotactic biopsy. Repeat imaging after changing the head position to allow scanning closer to the isocenter of the magnetic field showed decreased distortion, an improvement greater than that using the manufacturer's distortion correction algorithm on the initial images. Intraoperative MRI, and its requisite limitations in positioning, requires vigilance to detect possible distortion that could alter surgical outcomes if not identified and corrected prospectively.
authors.affiliation: Department of Radiology, University of Tennessee Health Science Center; Memphis, TN, USA - Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital; Memphis, TN, USA - achoudhri@uthsc.edu.
authors.forename: Asim F
authors.initials: AF
authors.lastname: Choudhri
authors.affiliation: College of Medicine, University of Tennessee Health Science Center; Memphis, TN, USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Chin
authors.affiliation: Department of Neurosurgery, University of Tennessee Health Science Center; Memphis, TN, USA - Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital; Memphis, TN, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Klimo
authors.affiliation: Department of Neurosurgery, University of Tennessee Health Science Center; Memphis, TN, USA - Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital; Memphis, TN, USA.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Boop
mesh_terms: D000293:Adolescent; D000465:Algorithms; D016477:Artifacts; D001254:Astrocytoma / Q000000981:diagnostic imaging* / Q000473:pathology; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D061705:Image-Guided Biopsy; D007430:Intraoperative Care; D008279:Magnetic Resonance Imaging; D008297:Male
keywords: artifact; brain tumor; intraoperative MRI; magnetic resonance imaging