Effect of in-painting on cortical thickness measurements in multiple sclerosis: A large cohort study

• Published in: Human brain mapping Vol. 36; no. 10; pp. 3749 - 3760
• Main Authors: Govindarajan, Koushik A., Datta, Sushmita, Hasan, Khader M., Choi, Sangbum, Rahbar, Mohammad H, Cofield, Stacey S., Cutter, Gary R., Lublin, Fred D., Wolinsky, Jerry S., Narayana, Ponnada A.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.10.2015; John Wiley & Sons, Inc; John Wiley and Sons Inc
• Subjects: Adolescent; Adult; Algorithms; Cerebral Cortex - pathology; Cohort Studies; cortical thickness; Double-Blind Method; Electromagnetic Fields; Female; FreeSurfer; Humans; Image Processing, Computer-Assisted - methods; lesion in-painting; Magnetic Resonance Imaging - methods; Male; Middle Aged; multiple sclerosis; Multiple Sclerosis - pathology; multiple sclerosis lesions; Multiple Sclerosis, Relapsing-Remitting - pathology; Multivariate Analysis; Young Adult; multiple sclerosis lesions; FreeSurfer; cortical thickness; multiple sclerosis; lesion in-painting
• ISSN: 1065-9471; 1097-0193; 1097-0193
• DOI: 10.1002/hbm.22875

A comprehensive analysis of the effect of lesion in‐painting on the estimation of cortical thickness using magnetic resonance imaging was performed on a large cohort of 918 relapsing‐remitting multiple sclerosis patients who participated in a phase III multicenter clinical trial. An automatic lesion in‐painting algorithm was developed and implemented. Cortical thickness was measured using the FreeSurfer pipeline with and without in‐painting. The effect of in‐painting was evaluated using FreeSurfer's paired analysis pipeline. Multivariate regression analysis was also performed with field strength and lesion load as additional factors. Overall, the estimated cortical thickness was different with in‐painting than without. The effect of in‐painting was observed to be region dependent, more significant in the left hemisphere compared to the right, was more prominent at 1.5 T relative to 3 T, and was greater at higher lesion volumes. Our results show that even for data acquired at 1.5 T in patients with high lesion load, the mean cortical thickness difference with and without in‐painting is ∼2%. Based on these results, it appears that in‐painting has only a small effect on the estimated regional and global cortical thickness. Hum Brain Mapp 36:3749–3760, 2015. © 2015 Wiley Periodicals, Inc.