Automated Segmentation of MS Lesions in MR Images Based on an Information Theoretic Clustering and Contrast Transformations

Technologies

Jason Hill²  Kevin Matlock²  Brian Nutter²  Sunanda Mitra¹  Yudong Zhang² 

[1] Department of Electrical & Computer Engineering, Texas Tech University, 2500 Broadway, Lubbock, TX 79409, USA;

关键词: segmentation;    unsupervised learning;    information theoretic clustering;    contrast transformations;    magnetic resonance images;    multiple sclerosis lesions;   

DOI  :  10.3390/technologies3020142

来源: mdpi

【 摘 要 】

Magnetic Resonance Imaging (MRI) plays a significant role in the current characterization and diagnosis of multiple sclerosis (MS) in radiological imaging. However, early detection of MS lesions from MRI still remains a challenging problem. In the present work, an information theoretic approach to cluster the voxels in MS lesions for automatic segmentation of lesions of various sizes in multi-contrast (T₁, T₂, PD-weighted) MR images, is applied. For accurate detection of MS lesions of various sizes, the skull-stripped brain data are rescaled and histogram manipulated prior to mapping the multi-contrast data to pseudo-color images. For automated segmentation of multiple sclerosis (MS) lesions in multi-contrast MRI, the improved jump method (IJM) clustering method has been enhanced via edge suppression for improved segmentation of white matter (WM), gray matter (GM), cerebrospinal fluid (CSF) and MS lesions if present. From this preliminary clustering, a pseudo-color to grayscale conversion is designed to equalize the intensities of the normal brain tissues, leaving the MS lesions as outliers. Binary discrete and 8-bit fuzzy labels are then assigned to segment the MS lesions throughout the full brain. For validation of the proposed method, three brains, with mild, moderate and severe hyperintense MS lesions labeled as ground truth, were selected. The MS lesions of mild, moderate and severe categories were detected with a sensitivity of 80%, and 96%, and 94%, and with the corresponding Dice similarity coefficient (DSC) of 0.5175, 0.8739, and 0.8266 respectively. The MS lesions can also be clearly visualized in a transparent pseudo-color computer rendered 3D brain.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.