title: Diffusion tensor imaging tractography in patients with intramedullary tumors: comparison with intraoperative findings and value for prediction of tumor resectability.
abstract: OBJECTIVE
  The aim of this retrospective study was to evaluate the predictive value of diffusion tensor (DT) imaging with respect to resectability of intramedullary spinal cord tumors and to determine the concordance of this method with intraoperative surgical findings.
  
  
  METHODS
  Diffusion tensor imaging was performed in 14 patients with intramedullary lesions of the spinal cord at different levels using a 3-T magnet. Routine MR imaging scans were also obtained, including unenhanced and enhanced T1-weighted images and T2-weighted images. Patients were classified according to the fiber course with respect to the lesion and their lesions were rated as resectable or nonresectable. These results were compared with the surgical findings (existence vs absence of cleavage plane). The interrater reliability was calculated using the kappa coefficient of Cohen.
  
  
  RESULTS
  Of the 14 patients (7 male, 7 female; mean age 49.2 +/- 15.5 years), 13 had tumors (8 ependymomas, 2 lymphomas, and 3 astrocytoma). One lesion was proven to be a multiple sclerosis plaque during further diagnostic workup. The lesions could be classified into 3 types according to the fiber course. In Type 1 (5 cases) fibers did not pass through the solid lesion. In Type 2 (3 cases) some fibers crossed the lesion, but most of the lesion volume did not contain fibers. In Type 3 (6 cases) the fibers were completely encased by tumor. Based on these results, 6 tumors were considered resectable, 7 were not. During surgery, 7 tumors showed a good cleavage plane, 6 did not. The interrater reliability (Cohen kappa) was calculated as 0.83 (p < 0.003), which is considered to represent substantial agreement. The mean duration of follow-up was 12.0 +/- 2.9. The median McCormick grade at the end of follow-up was II.
  
  
  CONCLUSIONS
  These preliminary data suggest that DT imaging in patients with spinal cord tumors is capable of predicting the resectability of the lesion. A further prospective study is needed to confirm these results and any effect on patient outcome.
authors.affiliation: H. Lee Moffitt Cancer Center and Research Institute, Neurooncology Program, 12902 Magnolia Drive, Tampa, Florida 33612, USA. frank.vrionis@moffitt.org
authors.forename: Matthias
authors.initials: M
authors.lastname: Setzer
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Murtagh
authors.forename: F Reed
authors.initials: FR
authors.lastname: Murtagh
authors.forename: Mohammed
authors.initials: M
authors.lastname: Eleraky
authors.forename: Surbhi
authors.initials: S
authors.lastname: Jain
authors.forename: Gerhard
authors.initials: G
authors.lastname: Marquardt
authors.forename: Volker
authors.initials: V
authors.lastname: Seifert
authors.forename: Frank D
authors.initials: FD
authors.lastname: Vrionis
mesh_terms: D001254:Astrocytoma / Q000473:pathology / Q000601:surgery; D056324:Diffusion Tensor Imaging / Q000295:instrumentation / Q000379:methods*; D004806:Ependymoma / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007432:Intraoperative Period; D008223:Lymphoma / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology / Q000601:surgery; D009434:Neural Pathways / Q000473:pathology; D015588:Observer Variation; D012189:Retrospective Studies; D013116:Spinal Cord / Q000473:pathology / Q000601:surgery; D013120:Spinal Cord Neoplasms / Q000473:pathology* / Q000601:surgery*; D013813:Therapy, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome