title: Inter- and intra-rater reliability of diffusion tensor imaging parameters in the normal pediatric spinal cord.
abstract: OBJECTIVE
  To assess inter- and intra-rater reliability (agreement) between two region of interest (ROI) methods in pediatric spinal cord diffusion tensor imaging (DTI).
  
  
  METHODS
  Inner-Field-of-View DTI data previously acquired from ten pediatric healthy subjects (mean age = 12.10 years) was used to assess for reliability. ROIs were drawn by two neuroradiologists on each subject data twice within a 3-mo interval. ROIs were placed on axial B0 maps along the cervical spine using free-hand and fixed-size ROIs. Agreement analyses for fractional anisotropy (FA), axial diffusivity, radial diffusivity and mean diffusivity were performed using intra-class-correlation (ICC) and Cronbach's alpha statistical methods.
  
  
  RESULTS
  Inter- and intra-rater agreement between the two ROI methods showed moderate (ICC = 0.5) to strong (ICC = 0.84). There were significant differences between raters in the number of pixels selected using free-hand ROIs (P < 0.05). However, no significant differences were observed in DTI parameter values. FA showed highest variability in ICC values (0.10-0.87). Cronbach's alpha showed moderate-high values for raters and ROI methods.
  
  
  CONCLUSIONS
  The study showed that high reproducibility in spinal cord DTI can be achieved, and demonstrated the importance of setting detailed methodology for post-processing DTI data, specifically the placement of ROIs.
authors.affiliation: Nadia Barakat, Pallav Shah, Scott H Faro, Devon Middleton, Feroze B Mohamed, Department of Radiology, Temple University, Philadelphia, PA 19140, United States.
authors.forename: Nadia
authors.initials: N
authors.lastname: Barakat
authors.affiliation: Nadia Barakat, Pallav Shah, Scott H Faro, Devon Middleton, Feroze B Mohamed, Department of Radiology, Temple University, Philadelphia, PA 19140, United States.
authors.forename: Pallav
authors.initials: P
authors.lastname: Shah
authors.affiliation: Nadia Barakat, Pallav Shah, Scott H Faro, Devon Middleton, Feroze B Mohamed, Department of Radiology, Temple University, Philadelphia, PA 19140, United States.
authors.forename: Scott H
authors.initials: SH
authors.lastname: Faro
authors.affiliation: Nadia Barakat, Pallav Shah, Scott H Faro, Devon Middleton, Feroze B Mohamed, Department of Radiology, Temple University, Philadelphia, PA 19140, United States.
authors.forename: John P
authors.initials: JP
authors.lastname: Gaughan
authors.affiliation: Nadia Barakat, Pallav Shah, Scott H Faro, Devon Middleton, Feroze B Mohamed, Department of Radiology, Temple University, Philadelphia, PA 19140, United States.
authors.forename: Devon
authors.initials: D
authors.lastname: Middleton
authors.affiliation: Nadia Barakat, Pallav Shah, Scott H Faro, Devon Middleton, Feroze B Mohamed, Department of Radiology, Temple University, Philadelphia, PA 19140, United States.
authors.forename: M J
authors.initials: MJ
authors.lastname: Mulcahey
authors.affiliation: Nadia Barakat, Pallav Shah, Scott H Faro, Devon Middleton, Feroze B Mohamed, Department of Radiology, Temple University, Philadelphia, PA 19140, United States.
authors.forename: Feroze B
authors.initials: FB
authors.lastname: Mohamed
keywords: Diffusion tensor imaging; Inter-rater; Intra-rater; Reliability; Reproducibility; Spinal cord