RT Journal Article SR Electronic T1 Evaluating the Effects of White Matter Multiple Sclerosis Lesions on the Volume Estimation of 6 Brain Tissue Segmentation Methods JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 1109 OP 1115 DO 10.3174/ajnr.A4262 VO 36 IS 6 A1 S. Valverde A1 A. Oliver A1 Y. Díez A1 M. Cabezas A1 J.C. Vilanova A1 L. Ramió-Torrentà A1 À. Rovira A1 X. Lladó YR 2015 UL http://www.ajnr.org/content/36/6/1109.abstract AB BACKGROUND AND PURPOSE: The accuracy of automatic tissue segmentation methods can be affected by the presence of hypointense white matter lesions during the tissue segmentation process. Our aim was to evaluate the impact of MS white matter lesions on the brain tissue measurements of 6 well-known segmentation techniques. These include straightforward techniques such as Artificial Neural Network and fuzzy C-means as well as more advanced techniques such as the Fuzzy And Noise Tolerant Adaptive Segmentation Method, fMRI of the Brain Automated Segmentation Tool, SPM5, and SPM8.MATERIALS AND METHODS: Thirty T1-weighted images from patients with MS from 3 different scanners were segmented twice, first including white matter lesions and then masking the lesions before segmentation and relabeling as WM afterward. The differences in total tissue volume and tissue volume outside the lesion regions were computed between the images by using the 2 methodologies.RESULTS: Total gray matter volume was overestimated by all methods when lesion volume increased. The tissue volume outside the lesion regions was also affected by white matter lesions with differences up to 20 cm3 on images with a high lesion load (≈50 cm3). SPM8 and Fuzzy And Noise Tolerant Adaptive Segmentation Method were the methods less influenced by white matter lesions, whereas the effect of white matter lesions was more prominent on fuzzy C-means and the fMRI of the Brain Automated Segmentation Tool.CONCLUSIONS: Although lesions were removed after segmentation to avoid their impact on tissue segmentation, the methods still overestimated GM tissue in most cases. This finding is especially relevant because on images with high lesion load, this bias will most likely distort actual tissue atrophy measurements.ANNArtificial Neural NetworkFANTASMFuzzy And Noise Tolerant Adaptive Segmentation MethodFASTFMRIB Automated Segmentation ToolFCMfuzzy C-meansH1Hospital Vall d'Hebron, Barcelona, SpainH2Hospital Universitari Dr. Josep Trueta, Girona, SpainH3Clinica Girona, Girona, SpainWMLwhite matter lesion