Inter- and intra-rater reliability of diffusion tensor imaging parameters in the normal pediatric spinal cord Nadia Barakat, Pallav Shah, Scott H Faro, John P Gaughan, Devon Middleton, MJ Mulcahey, Feroze B Mohamed Nadia Barakat, Pallav Shah, Scott H Faro, Devon Middleton, Feroze B Mohamed, Department of Radiology, Temple University, Philadelphia, PA 19140, United States Nadia Barakat, John P Gaughan, Biostatistics Consulting Center, Temple University School of Medicine, Philadelphia, PA 19140, United States MJ Mulcahey, Thomas Jefferson University School of Health Professions, Philadelphia, PA 19107, United States Author contributions: All the authors solely contributed to this paper. Supported by The Shriners Hospitals for Children, No. #8956. Institutional review board statement: Subjects and their parents provided written informed assent and consent of the IRB- approved protocol. Informed consent statement: Subjects and their parents provided written informed assent and consent of the IRB- approved protocol. Confict-of-interest statement: All the authors participated in this work do not have any confict of interest. Data sharing statement: All the authors participated in this work do not have any data sharing. Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/ licenses/by-nc/4.0/ Correspondence to: Nadia Barakat, PhD, Department of Radiology, Temple University, 3401 N. Broad St., Philadelphia, PA 19140, United States. nadia.barakat@temple.edu Telephone: +1-215-7079047 Received: February 11, 2015 Peer-review started: February 11, 2015 First decision: March 6, 2015 Revised: June 24, 2015 Accepted: July 29, 2015 Article in press: August 3, 2015 Published online: September 28, 2015 Abstract AIM: To assess inter- and intra-rater reliability (agree- ment) 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 fxed-size ROIs. Agreement analyses for fractional anisotropy (FA), axial diffusivity, radial diffusivity and mean diffusivity were performed using intra-class-corre- lation (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 signifcant 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. CONCLUSION: The study showed that high reprodu- cibility in spinal cord DTI can be achieved, and demon- ORIGINAL ARTICLE World Journal of Radiology WJR Submit a Manuscript: http://www.wjgnet.com/esps/ Help Desk: http://www.wjgnet.com/esps/helpdesk.aspx DOI: 10.4329/wjr.v7.i9.279 World J Radiol 2015 September 28; 7(9): 279-285 ISSN 1949-8470 (online) © 2015 Baishideng Publishing Group Inc. All rights reserved. 279 September 28, 2015|Volume 7|Issue 9| WJR|www.wjgnet.com Retrospective Cohort Study