A Sensitive and Automatic White Matter Fiber Tracts Model for Longitudinal Analysis of Diffusion Tensor Images in Multiple Sclerosis

• Published in: PloS one 2016, Vol.11 (5)
• Main Authors: Stamile, Claudio, Kocevar, Gabriel, Cotton, François, Durand-Dubief, Françoise, Hannoun, Salem, Frindel, Carole, Guttmann, Charles R G, Rousseau, David, Sappey-Marinier, Dominique
• Format: Article
• Language: English
• Subjects: Bioengineering; Imaging; Life Sciences; Neurobiology; Neurons and Cognition
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0156405.t001

Diffusion tensor imaging (DTI) is a sensitive tool for the assessment of microstructural alterations in brain white matter (WM). We propose a new processing technique to detect, local and global longitudinal changes of diffusivity metrics, in homologous regions along WM fiber-bundles. To this end, a reliable and automatic processing pipeline was developed in three steps: 1) co-registration and diffusion metrics computation, 2) tractography, bundle extraction and processing, and 3) longitudinal fiber-bundle analysis. The last step was based on an original Gaussian mixture model providing a fine analysis of fiber-bundle cross-sections, and allowing a sensitive detection of longitudinal changes along fibers. This method was tested on simulated and clinical data. High levels of F-Measure were obtained on simulated data. Experiments on cortico-spinal tract and inferior fronto-occipital fasciculi of five patients with Multiple Sclerosis (MS) included in a weekly follow-up protocol highlighted the greater sensitivity of this fiber scale approach to detect small longitudinal alterations.