title: Application of T2 relaxometry in lateralization and localization of mesial temporal lobe epilepsy and corresponding comparison with MR volumetry.
abstract: BACKGROUND
  Magnetic resonance (MR) volumetry is insensitive to subtle mesial temporal sclerosis (MTS), while T2 relaxometry is potential useful in detecting MTS, especially MTS in early course.
  
  
  OBJECTIVE
  To explore and compare the feasibility of T2 relaxometry and MR volumetry in evaluation of mesial temporal lobe epilepsy (MTLE) and lateralization of the epileptogenic zone, so as to optimize and enhance lesion depiction.
  
  
  METHODS
  For the 17 unilateral MTLE patients and 14 normal participants, the hippocampus and amygdala were contoured on axial T2-weighted (T2W) images and then co-registered onto T2 relaxation maps. Abnormal is defined as an elevated asymmetric ratio of larger than 2 SD. Visual and quantitative volumetric assessment were combined as outcomes of MR volumetry to distinguish MR-positive and MR-negative lesions. Operative and pathological findings were used as gold standard.
  
  
  RESULTS
  T2 values of lesions were significantly elevated. In lateralizing the epileptogenic zones, T2 relaxometry yielded an overall accuracy of 94.1% (sensitivity 92.6%, specificity 100%), and MR volumetry yielded an overall accuracy of 82.4% (sensitivity 88.9%, specificity 57.1%), meaning a better performance of T2 relaxometry (P < 0.001, by chi-square test). For pathologically sclerotic structures, most (25/27) were recognized by T2 relaxometry, while 24 of 27 sclerotic structures were detected via MR volumetry. MR volumetry wrongly discerned three normal regions as MTS, while one MR-negative sclerotic hippocampus was detected by T2 relaxometry.
  
  
  CONCLUSIONS
  T2 relaxometry is feasible in non-invasive lateralization of epileptogenic zone, and more advantaged than MR volumetry in detecting MR-negative lesions, facilitating prompt diagnosis and longitudinal disease monitoring.
authors.affiliation: Department of Radiology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Hubei, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.affiliation: Reproductive Center, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Hubei, PR China.
authors.forename: Guilian
authors.initials: G
authors.lastname: Yu
authors.affiliation: Department of Radiology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Hubei, PR China.
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Radiology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Hubei, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Radiology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Hubei, PR China chenhuixyzxyy@126.com.
authors.forename: Guangming
authors.initials: G
authors.lastname: Li
mesh_terms: D000328:Adult; D000679:Amygdala / Q000000981:diagnostic imaging; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D006624:Hippocampus / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
keywords: T2; lateralization; mesial temporal lobe epilepsy (MTLE); relaxometry; sclerosis; volumetry