Application of neurite orientation dispersion and density imaging in assessing glioma grades and cellular proliferation

Objective To explore the performance of neurite orientation dispersion and density imaging (NODDI) in grading gliomas and to evaluate the cellular proliferation. Methods NODDI and diffusion-weighted imaging were performed on 79 patients with histopathologically proven gliomas. Parameter maps of intracellular volume fraction (ICVF), orientation dispersion index (ODI), and apparent diffusion coefficient (ADC) were calculated. Regions of interest were placed in the most solid part of the tumor. These metrics were normalized to the contralateral normal-appearing white matter and correlated with Ki-67 expression. Results ICVF and ODI increased as tumor grades increased, whereas ADC decreased with the increase of tumor grades. Significant differences in normalized ICVF and ODI were observed between low-grade gliomas and high-grade gliomas (ICVF: 0.208 ± 0.104 vs. 0.718 ± 0.234; ODI: 0.952 ± 0.428 vs. 1.767 ± 0.636, P Conclusions NODDI is a promising method in grading gliomas and predicting cellular proliferation. These results may be of great significance for the clinical diagnosis and treatment of gliomas.