Inter-and intra-rater reliability of diffusion tensor imaging parameters in the normal pediatric spinal cord

• Published in: World journal of radiology Vol. 7; no. 9; pp. 279 - 285
• Main Authors: Barakat, Nadia, Shah, Pallav, Faro, Scott H, Gaughan, John P, Middleton, Devon, Mulcahey, M J, Mohamed, Feroze B
• Format: Journal Article
• Language: English
• Published: United States Baishideng Publishing Group Inc 28-09-2015
• Subjects: Diffusion; imaging;Reproducibility;Reliabili; Retrospective Cohort Study; tensor; Inter-rater; Spinal cord; Intra-rater; Reliability; Reproducibility; Diffusion tensor imaging
• ISSN: 1949-8470; 1949-8470
• DOI: 10.4329/wjr.v7.i9.279

AIM: 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. CONCLUSION: 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.