title: Diffusion tensor tractography-based analysis of the cingulum: clinical utility and findings in traumatic brain injury with chronic sequels.
abstract: BACKGROUND
  To evaluate the clinical utility of quantitative diffusion tensor tractography (DTT) and tractography-based core analysis (TBCA) of the cingulum by defining the reproducibility, normal values, and findings in traumatic brain injury (TBI).
  
  
  METHODS
  Eighty patients with TBI and normal routine MRI and 78 controls underwent MRI at 3T. To determine reproducibility, 12 subjects were scanned twice. Superior (SC) and inferior (IC) cingulum were analyzed separately by DTT (fractional anisotropy (FA) thresholds 0.15 and 0.30). TBCA was performed from volumes defined by tractography with gradually changed FA thresholds. FA values were correlated with clinical and neuropsychological data.
  
  
  RESULTS
  The lowest coefficient of variation was obtained at DTT threshold 0.30 (2.0 and 2.4 % for SC and IC, respectively), but in proportion to standard deviations of normal controls, the reproducibility of TBCA was better in SC and similar to that of DTT in IC. In patients with TBI, volume reduction with loss of peripheral fibers was relatively common; mean FA was mostly normal in these tractograms. The frequency of FA reductions (>2 SD) was in DTT smaller than in TBCA, in which FA decrease was present in 42 (13.1 %) of the 320 measurements. Central FA values in SC predicted visuoperceptual ability, and those in left IC predicted cognitive speed, language, and communication ability (p < 0.05).
  
  
  CONCLUSIONS
  Tractography-based measurements have sufficient reproducibility for demonstration of severe abnormalities of the cingulum. TBCA is preferential for clinical FA analysis, because it measures corresponding areas in patients and controls without inaccuracies due to trauma-induced structural changes.
authors: Department of Radiology, Turku University Hospital, Turku, Finland, kurti@suomi24.fi.
authors: Timo
authors: T
authors: Kurki
authors: Leena
authors: L
authors: Himanen
authors: Elina
authors: E
authors: Vuorinen
authors: Anna
authors: A
authors: Myllyniemi
authors: Anna-Riitta
authors: AR
authors: Saarenketo
authors: Tommi
authors: T
authors: Kauko
authors: Nina
authors: N
authors: Brandstack
authors: Olli
authors: O
authors: Tenovuo
mesh_terms: D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D001930:Brain Injuries / Q000150:complications* / Q000473:pathology* / Q000523:psychology; D016022:Case-Control Studies; D056324:Diffusion Tensor Imaging; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D015203:Reproducibility of Results; D055815:Young Adult