title: Intraoperative localization of subcortical brain lesions.
abstract: BACKGROUND
  Some brain tumors may grow immediately beneath the cortical surface without distorting its appearance. Intraoperative image guidance promotes safe resection. We have developed MRI-based corticotopography (MRI-bct), to localize lesions during surgery, using simple, non-dedicated equipment, to match a three-dimensional reconstruction with the corresponding appearance of the brain cortex.
  
  
  METHODS
  Forty-six patients underwent resection of subcortical brain lesions, aided by MRI-bct. The lesions had a maximum diameter less than 3 cm, were subcortical but no deeper than the floor of the nearest cerebral sulcus. Each patient had a volumetric MRI scan with and without contrast administration. Data sets were transferred to a laptop personal computer and processed using a rendering software. At operation, the three-dimensional model of the brain, including a surface overlay of the lesion, was matched to the exposed brain surface. After its exact relationship with the overlying sulcal pattern was defined, the lesion was localized and resected. In selected patients, the procedure was coupled with functional brain mapping.
  
  
  RESULTS
  Data processing took from 10 to 15 min and could be done whenever convenient before operation. Surface matching between the surgical field and the reformatted MRI always required less than 5 min and was done near the operating table. In all patients, the lesion was identified at the first attempt, through a small corticotomy, regardless of the brain shift after dural opening.
  
  
  CONCLUSIONS
  MRI-bct is a practical, time-saving neuronavigational aid ideal for localizing superficial lesions underlying the cerebral cortex because it unmistakably characterizes the adjacent sulcal anatomy.
authors.affiliation: Università degli Studi di Roma Sapienza, Cattedra di Neurochirurgia - IRCCS Neuromed, Pozzilli, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Esposito
authors.forename: S
authors.initials: S
authors.lastname: Paolini
authors.forename: R
authors.initials: R
authors.lastname: Morace
authors.forename: C
authors.initials: C
authors.lastname: Colonnese
authors.forename: E
authors.initials: E
authors.lastname: Venditti
authors.forename: V
authors.initials: V
authors.lastname: Calistri
authors.forename: G
authors.initials: G
authors.lastname: Cantore
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001931:Brain Mapping / Q000295:instrumentation; D001932:Brain Neoplasms / Q000175:diagnosis / Q000556:secondary / Q000601:surgery*; D002540:Cerebral Cortex / Q000473:pathology / Q000601:surgery*; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D005909:Glioblastoma / Q000175:diagnosis / Q000601:surgery*; D006392:Hemangioma, Cavernous / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008297:Male; D008838:Microcomputers; D008875:Middle Aged; D018302:Neoplasms, Neuroepithelial / Q000175:diagnosis / Q000601:surgery*; D038361:Neuronavigation / Q000295:instrumentation*; D011183:Postoperative Complications / Q000209:etiology; D012984:Software; D013996:Time and Motion Studies