title: Arcuate fasciculus laterality by diffusion tensor imaging correlates with language laterality by functional MRI in preadolescent children.
abstract: BACKGROUND
  Language lateralization is unique to humans. Functional MRI (fMRI) and diffusion tensor imaging (DTI) enable the study of language areas and white matter fibers involved in language, respectively. The objective of this study was to correlate arcuate fasciculus (AF) laterality by diffusion tensor imaging with that by fMRI in preadolescent children which has not yet been reported.
  
  
  METHODS
  Ten children between 8 and 12 years were subjected to fMRI and DTI imaging using Siemens 1.5 T MRI. Two language fMRI paradigms--visual verb generation and word pair task--were used. Analysis was done using SPM8 software. In DTI, the fiber volume of the arcuate fasciculus (AFV) and fractional anisotropy (FA) was measured. The fMRI Laterality Index (fMRI-LI) and DTI Laterality Index (DTI-LI) were calculated and their correlation assessed using the Pearson Correlation Index.
  
  
  RESULTS
  Of ten children, mean age 10.6 years, eight showed left lateralization while bilateral language lateralization was seen in two. AFV by DTI was more on the left side in seven of the eight children who had left lateralization by fMRI. DTI could not trace the AF in one child. Of the two with bilateral language lateralization on fMRI, one showed larger AFV on the right side while the other did not show any asymmetry. There was a significant correlation (p < 0.02) between fMRI-LI and DTI-LI. Group mean of AFV by DTI was higher on the left side (2659.89 ± 654.75 mm(3)) as compared to the right (1824.11 ± 582.81 mm(3)) (p < 0.01).
  
  
  CONCLUSIONS
  Like fMRI, DTI also reveals language laterality in children with a high degree of correlation between the two imaging modalities.
authors.affiliation: Department of Radiology, Government Medical College Hospital, Trivandrum, Kerala, India.
authors.forename: Ruma Madhu
authors.initials: RM
authors.lastname: Sreedharan
authors.forename: Amitha C
authors.initials: AC
authors.lastname: Menon
authors.forename: Jija S
authors.initials: JS
authors.lastname: James
authors.forename: Chandrasekharan
authors.initials: C
authors.lastname: Kesavadas
authors.forename: Sanjeev V
authors.initials: SV
authors.lastname: Thomas
mesh_terms: D001931:Brain Mapping / Q000379:methods*; D002648:Child; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007802:Language; D008297:Male; D064847:Multimodal Imaging / Q000379:methods; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013702:Temporal Lobe / Q000033:anatomy & histology / Q000502:physiology; D066127:White Matter / Q000033:anatomy & histology* / Q000502:physiology*