Orientation Dispersion Index identifies sub-areas in the edema tissue of glioblastoma

Motivation: Edema tissue in glioblastoma is not included in surgical resection, even though tumor cells infiltration could be mediated by it. Goal(s): The aim of the study is to investigate the heterogeneity of edema. Approach: Clustering analysis within edema is performed on the orientation dispersion index derived from diffusion magnetic resonance imaging. Then, a non-parametric statistical test is carried out to assess the difference between the resulting edema sub-tissues (e.g., clusters). Results: Two spatially separated clusters are found for all subjects. Statistically significant differences are observed between each couple of resulting clusters. Impact: Edema is not a healthy tissue and the possibility of identifying sub-tissues within it could aid clinical practice and pre-surgical planning. This study works at single-subject level, allowing the focus on the specific glioblastoma cases.