title: Choice of diffusion tensor estimation approach affects fiber tractography of the fornix in preterm brain.
abstract: OBJECTIVE
  Neonatal DTI enables quantitative assessment of microstructural brain properties. Although its use is increasing, it is not widely known that vast differences in tractography results can occur, depending on the diffusion tensor estimation methodology used. Current clinical work appears to be insufficiently focused on data quality and processing of neonatal DTI. To raise awareness about this important processing step, we investigated tractography reconstructions of the fornix with the use of several estimation techniques. We hypothesized that the method of tensor estimation significantly affects DTI tractography results.
  
  
  METHODS
  Twenty-eight DTI scans of infants born <29 weeks of gestation, acquired at 30-week postmenstrual age and without intracranial injury observed, were prospectively collected. Four diffusion tensor estimation methods were applied: 1) linear least squares; 2) weighted linear least squares; 3) nonlinear least squares, and 4) robust estimation of tensors by outlier rejection. Quality of DTI data and tractography results were evaluated for each method.
  
  
  RESULTS
  With nonlinear least squares and robust estimation of tensors by outlier rejection, significantly lower mean fractional anisotropy values were obtained than with linear least squares and weighted linear least squares. Visualized quality of tract reconstruction was significantly higher by use of robust estimation of tensors by outlier rejection and correlated with quality of DTI data.
  
  
  CONCLUSIONS
  Quality assessment and choice of processing methodology have considerable impact on neonatal DTI analysis. Dedicated acquisition, quality assessment, and advanced processing of neonatal DTI data must be ensured before performing clinical analyses, such as associating microstructural brain properties with patient outcome.
authors.affiliation: From the Division of Neonatology, Department of Pediatrics (A.P., K.P., P.G., A.M.H., J.D.), Erasmus Medical Center-Sophia, Rotterdam, The NetherlandsDepartments of Radiology (A.P., M.H.L., A.M.H., G.P.K., J.D.).
authors.forename: A
authors.initials: A
authors.lastname: Plaisier
authors.affiliation: From the Division of Neonatology, Department of Pediatrics (A.P., K.P., P.G., A.M.H., J.D.), Erasmus Medical Center-Sophia, Rotterdam, The Netherlands.
authors.forename: K
authors.initials: K
authors.lastname: Pieterman
authors.affiliation: Departments of Radiology (A.P., M.H.L., A.M.H., G.P.K., J.D.).
authors.forename: M H
authors.initials: MH
authors.lastname: Lequin
authors.affiliation: From the Division of Neonatology, Department of Pediatrics (A.P., K.P., P.G., A.M.H., J.D.), Erasmus Medical Center-Sophia, Rotterdam, The NetherlandsDepartment of Pediatrics (P.G.), Koningin Paola Children's Hospital, Antwerp, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Govaert
authors.affiliation: From the Division of Neonatology, Department of Pediatrics (A.P., K.P., P.G., A.M.H., J.D.), Erasmus Medical Center-Sophia, Rotterdam, The NetherlandsDepartments of Radiology (A.P., M.H.L., A.M.H., G.P.K., J.D.).
authors.forename: A M
authors.initials: AM
authors.lastname: Heemskerk
authors.affiliation: Neonatology (I.K.M.R.), Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: I K M
authors.initials: IK
authors.lastname: Reiss
authors.affiliation: Departments of Radiology (A.P., M.H.L., A.M.H., G.P.K., J.D.).
authors.forename: G P
authors.initials: GP
authors.lastname: Krestin
authors.affiliation: Image Sciences Institute (A.L.), University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Leemans
authors.affiliation: From the Division of Neonatology, Department of Pediatrics (A.P., K.P., P.G., A.M.H., J.D.), Erasmus Medical Center-Sophia, Rotterdam, The NetherlandsDepartments of Radiology (A.P., M.H.L., A.M.H., G.P.K., J.D.) j.dudink@erasmusmc.nl.
authors.forename: J
authors.initials: J
authors.lastname: Dudink
mesh_terms: D000465:Algorithms; D016477:Artifacts; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D020712:Fornix, Brain / Q000166:cytology* / Q000196:embryology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007234:Infant, Premature; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity