title: Diffusion abnormalities and reduced volume of the ventral cingulum bundle in agenesis of the corpus callosum: a 3T imaging study.
abstract: OBJECTIVE
  Patients with agenesis of the corpus callosum (AgCC) exhibit cognitive and behavioral impairments that are not replicated by surgical transection of the callosum, suggesting that other anatomic changes may contribute to the observed clinical findings. The purpose of this study was to determine whether the ventral cingulum bundle (VCB) is affected in patients with AgCC by using diffusion tensor imaging (DTI) and volumetry.
  
  
  METHODS
  Twelve participants with AgCC (8 males and 4 females; mean age, 30 +/- 20) and 12 control subjects matched for age and sex (mean age, 37 +/- 19) underwent MR imaging and DTI at 3T. 3D fiber tracking of the VCB was generated from DTI and the average fractional anisotropy (FA) was computed for the tracked fibers. Additionally, the volume, cross-sectional area, and length of the VCB were measured by manually drawn regions of interest on thin-section coronal T1-weighted images. The Student t test was used to compare these results.
  
  
  RESULTS
  Compared with controls, subjects with AgCC demonstrated significantly reduced FA in the right VCB (P = .0098) and reduced volume and cross-sectional areas of both the left and right VCB (P < .001 for all metrics). The length of the VCB was also significantly reduced in the complete AgCC subgroup compared with controls (P = .030 in the right and P = .046 in the left, respectively).
  
  
  CONCLUSIONS
  Patients with AgCC have abnormal microstructure and reduced volume of the VCB, suggesting that abnormalities in intrahemispheric white matter tracts may be an important contributor to the clinical syndrome in patients with AgCC.
authors.affiliation: Department of Radiology, University of California, San Francisco, San Francisco, CA 94143-0628, USA. nakatay-tky@umin.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Nakata
authors.forename: A J
authors.initials: AJ
authors.lastname: Barkovich
authors.forename: M
authors.initials: M
authors.lastname: Wahl
authors.forename: Z
authors.initials: Z
authors.lastname: Strominger
authors.forename: R J
authors.initials: RJ
authors.lastname: Jeremy
authors.forename: M
authors.initials: M
authors.lastname: Wakahiro
authors.forename: P
authors.initials: P
authors.lastname: Mukherjee
authors.forename: E H
authors.initials: EH
authors.lastname: Sherr
mesh_terms: D000328:Adult; D061085:Agenesis of Corpus Callosum; D003337:Corpus Callosum / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D009929:Organ Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity