title: SISCOM technique with a variable Z score improves detectability of focal cortical dysplasia: a comparative study with MRI.
abstract: OBJECTIVE
  Focal cortical dysplasia (FCD) is one of the causes of epilepsy, but its diagnosis by MRI remains difficult. The purpose of this study was to evaluate the use of subtraction ictal SPECT coregistered to MRI (SISCOM) and MRI to detect the epileptogenic focus in patients with FCD.
  
  
  METHODS
  MRI and SISCOM findings of 20 patients with pathologically proven FCD were retrospectively reviewed. MRI was visually assessed for detecting FCD. SISCOM was evaluated by a new method selecting a higher standard deviation (Z score) area as the epileptogenic focus. We scored the detectability in both SISCOM and MRI while referring to the pathology.
  
  
  RESULTS
  Sixteen patients agreed with pathology on SISCOM and 14 patients on MRI. Although MRI could not point out foci in two cases of FCD type I, SISCOM could do so in both of them. A combined diagnosis of SISCOM and MRI agreed with the pathology in 18 patients.
  
  
  CONCLUSIONS
  Narrowing the target by elevating the Z score on SISCOM seems to be an appropriate method to detect the foci without the need for expertise of radiologists. We recommend this combined method of SISCOM and MRI for presurgical evaluation in patients with FCD.
authors.affiliation: Department of Radiology, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi-cyo, Kodaira, Tokyo, 187-8511, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kimura
authors.forename: Noriko
authors.initials: N
authors.lastname: Sato
authors.forename: Kimiteru
authors.initials: K
authors.lastname: Ito
authors.forename: Kouhei
authors.initials: K
authors.lastname: Kamiya
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nakata
authors.forename: Yuko
authors.initials: Y
authors.lastname: Saito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsuda
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugai
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sasaki
authors.forename: Hideharu
authors.initials: H
authors.lastname: Sugimoto
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004827:Epilepsy / Q000209:etiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D054220:Malformations of Cortical Development / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D012189:Retrospective Studies; D013382:Subtraction Technique; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult