title: Voxel-based morphometric magnetic resonance imaging (MRI) postprocessing in MRI-negative epilepsies.
abstract: OBJECTIVE
  In the presurgical workup of magnetic resonance imaging (MRI)-negative (MRI(-) or "nonlesional") pharmacoresistant focal epilepsy (PFE) patients, discovering a previously undetected lesion can drastically change the evaluation and likely improve surgical outcome. Our study utilizes a voxel-based MRI postprocessing technique, implemented in a morphometric analysis program (MAP), to facilitate detection of subtle abnormalities in a consecutive cohort of MRI(-) surgical candidates.
  
  
  METHODS
  Included in this retrospective study was a consecutive cohort of 150 MRI(-) surgical patients. MAP was performed on T1-weighted MRI, with comparison to a scanner-specific normal database. Review and analysis of MAP were performed blinded to patients' clinical information. The pertinence of MAP(+) areas was confirmed by surgical outcome and pathology.
  
  
  RESULTS
  MAP showed a 43% positive rate, sensitivity of 0.9, and specificity of 0.67. Overall, patients with the MAP(+) region completely resected had the best seizure outcomes, followed by the MAP(-) patients, and patients who had no/partial resection of the MAP(+) region had the worst outcome (p < 0.001). Subgroup analysis revealed that visually identified subtle findings are more likely correct if also MAP(+) . False-positive rate in 52 normal controls was 2%. Surgical pathology of the resected MAP(+) areas contained mainly non-balloon-cell focal cortical dysplasia (FCD). Multiple MAP(+) regions were present in 7% of patients.
  
  
  CONCLUSIONS
  MAP can be a practical and valuable tool to: (1) guide the search for subtle MRI abnormalities and (2) confirm visually identified questionable abnormalities in patients with PFE due to suspected FCD. A MAP(+) region, when concordant with the patient's electroclinical presentation, should provide a legitimate target for surgical exploration.
authors: Epilepsy Center, Cleveland Clinic, Cleveland, OH.
authors: Z Irene
authors: ZI
authors: Wang
authors: Department of Diagnostic Radiology, Mellen Imaging Center, Cleveland Clinic, Cleveland, OH.
authors: Stephen E
authors: SE
authors: Jones
authors: Sanford USD Medical Center, Sioux Falls, SD.
authors: Zeenat
authors: Z
authors: Jaisani
authors: Epilepsy Center, Cleveland Clinic, Cleveland, OH.
authors: Imad M
authors: IM
authors: Najm
authors: Department of Anatomic Pathology, Cleveland Clinic, Cleveland, OH.
authors: Richard A
authors: RA
authors: Prayson
authors: Epilepsy Center, Cleveland Clinic, Cleveland, OH.
authors: Richard C
authors: RC
authors: Burgess
authors: Epilepsy Center, Cleveland Clinic, Cleveland, OH.
authors: Balu
authors: B
authors: Krishnan
authors: Clinic of Neurology, Epilepsy Center, Clinical Center of Serbia, Belgrade, Serbia.
authors: Aleksandar
authors: A
authors: Ristic
authors: Department of Neurology, Westmead Hospital, Sydney, Australia.
authors: Chong H
authors: CH
authors: Wong
authors: Department of Neurosurgery, Cleveland Clinic, Cleveland, OH.
authors: William
authors: W
authors: Bingaman
authors: Department of Neurosurgery, Cleveland Clinic, Cleveland, OH.
authors: Jorge A
authors: JA
authors: Gonzalez-Martinez
authors: Epilepsy Center, Cleveland Clinic, Cleveland, OH.
authors: Andreas V
authors: AV
authors: Alexopoulos
mesh_terms: D000328:Adult; D000368:Aged; D004828:Epilepsies, Partial / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult