title: Statistical SPECT processing in MRI-negative epilepsy surgery.
abstract: OBJECTIVE
  To evaluate the benefit of statistical SPECT processing over traditional subtraction methods, we compared ictal-interictal SPECT analyzed by statistical parametric mapping (SPM) (ISAS), statistical ictal SPECT coregistered to MRI (STATISCOM), and subtraction ictal-interictal SPECT coregistered with MRI (SISCOM) in patients with MRI-negative focal temporal lobe epilepsy (nTLE) and extratemporal lobe epilepsy (nETLE).
  
  
  METHODS
  We retrospectively identified 49 consecutive cases of drug-resistant focal epilepsy that had a negative preoperative MRI and underwent interictal and ictal SPECT prior to resective epilepsy surgery. Interictal and ictal SPECT scans were analyzed using SISCOM, ISAS, and STATISCOM to create hyperperfusion and hypoperfusion maps for each patient. Reviewers blinded to clinical data and the SPECT analysis method marked the site of probable seizure origin and indicated their confidence in the localization.
  
  
  RESULTS
  In nTLE and nETLE, the hyperperfusions detected by STATISCOM (71% nTLE, 57% nETLE) and ISAS (67% nTLE, 53% nETLE) were more often colocalized with surgery resection site compared to SISCOM (38% nTLE, 36% nETLE). In nTLE, localization of the hyperperfusion to the region of surgery was associated with an excellent outcome for STATISCOM (p = 0.005) and ISAS (p = 0.027), but not in SISCOM (p = 0.071). This association was not present in nETLE for any method.
  
  
  CONCLUSIONS
  In an unselected group of patients with normal MRI and focal epilepsy, SPM-based methods of SPECT processing showed better localization of SPECT hyperperfusion to surgical resection site and higher interobserver agreement compared to SISCOM. These results show the benefit of statistical SPECT processing methods and further highlight the challenge of nETLE.
authors: From the Departments of Neurology (V.S., B.H.B., D.T.J., G.D.C., L.C.W.-K., J.W.B., E.L.S., G.A.W.) and Radiology (M.L.S., B.P.M., R.E.W.) and Biomedical Imaging Resource (S.S., D.P.H., D.R.H., R.A.R.), Mayo Clinic, Rochester, MN; International Clinical Research Center (V.S., D.H.), St. Anne's University Hospital, Brno; and the Department of Neurology (V.S.), 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague, Czech Republic.
authors: Vlastimil
authors: V
authors: Sulc
authors: Samantha
authors: S
authors: Stykel
authors: Dennis P
authors: DP
authors: Hanson
authors: Benjamin H
authors: BH
authors: Brinkmann
authors: David T
authors: DT
authors: Jones
authors: David R
authors: DR
authors: Holmes
authors: Richard A
authors: RA
authors: Robb
authors: Matthew L
authors: ML
authors: Senjem
authors: Brian P
authors: BP
authors: Mullan
authors: Robert E
authors: RE
authors: Watson
authors: Daniel
authors: D
authors: Horinek
authors: Gregory D
authors: GD
authors: Cascino
authors: Lily C
authors: LC
authors: Wong-Kisiel
authors: Jeffrey W
authors: JW
authors: Britton
authors: Elson L
authors: EL
authors: So
authors: Gregory A
authors: GA
authors: Worrell
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D004569:Electroencephalography; D004827:Epilepsy / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome; D055815:Young Adult