Utilizing multiple diffusion metrics in evaluation of corticospinal tract injury in patients with glioblastoma

This study aimed to evaluate the efficacy of diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), neurite orientation dispersion and density imaging (NODDI), and mean apparent propagator-magnetic resonance imaging (MAP-MRI) in detecting CST injury caused by GBM and to compare their performances.

We enrolled 76 patients diagnosed with GBM with motor weakness (MW, n = 22) or normal motor (NM, n = 54). Bilateral CSTs were reconstructed, and a comparative analysis of diffusion parameters was performed based on four imaging models between affected and healthy sides. Relative diffusion parameters were assessed in the MW and NM groups. Statistical analyses were performed using SPSS software.

Significant alterations in most diffusion parameters of DTI, DKI, NODDI, and MAP-MRI were observed in the affected CST group compared to the healthy CST group (p < 0.05). Notable differences in the relative diffusion parameters were observed between the MW and NW groups across all four imaging models (p < 0.05). Specifically, DKI-based relative mean kurtosis (MK) exhibited a higher area under the curve (0.813), demonstrating greater sensitivity and specificity, which significantly positively correlated with muscle strength. DeLong^'s test revealed a significant performance difference between DKI and DTI.

Diffusion parameters from DTI, DKI, NODDI, and MAP-MRI are useful for evaluating CST injury. While DKI-derived MK and NODDI-derived ICVF achieved identical high AUC values, MK exhibited a more balanced sensitivity-specificity profile for assessing microstructural alterations in CST injury, this advantage of DKI may better address clinical demands, potentially aiding in surgical planning and preserving motor function in patients with GBM.