Correlation between diffusion kurtosis imaging and clinical pathological features of rectal adenocarcinoma

Abstract

Objective To investigate the potential relationships between diffusional kurtosis imaging(DKI)-derived parameters and apparent diffusion coefficient(ADC)values and clinicopathological prognostic factors in patients with rectal adenocarcinoma, and provide some reference for the clinical prediction of the malignant degree of rectal cancer. Methods One hundred and twenty-two consecutive patients with rectal adenocarcinoma who underwent MRI examination in the Shanxi Province Tumor Hospital from November 2016 to April 2017 were retrospectively evaluated. Among them, there were 48 females(39.3%) and 74 males(60.7%) with aged of 42-81 years. The quantitative parameters including mean diffusivity(MD), mean kurtosis(MK)and ADC were measured with relevant software. Student's t-test or Mann-Whitney U-test, receiver operating characteristic(ROC)curves, and Spearman's correlation were used for statistical analysis. Results The ADC and MD were negatively correlated with nodal involvement and tumor T stages(all P values<0.05). Similarly, there were statistically significant differences between MD values in different histopathological grades and negatively correlated(r=-0.210, P<0.05). With the increase of histological grade, lymph node involvement, the presence of lymphangiovascular invasion (LVI) and circumferential margin(CRM), the MK values increased correspondingly, and these difference were statistically significant and positively correlated(r=0.478, 0.206, 0.228, all P values<0.05). The MD, MK and ADC were correlated with nodal involvement(all P values<0.01). The area under the ROC curve of MK is 0.784(95%CI 0.703-0.865), MK showed relatively higher area under the curve and higher specificity than other quantitative parameters for differentiation of lesions with nodal involvement. When the cutoff of MD was 0.984, the corresponding sensitivity and specificity were 65.9% and 88.7% respectively. Conclusions DKI-derived parameters and ADC values, especially the MK parameters, are associated with important prognostic factors of rectal cancer, and may has a certain significance for predicting the prognosis of patients with rectal cancer. Key words: Rectal neoplasms; Diffusion magnetic resonance imaging; Diffusion weighted imaging; Diffusion kurtosis imaging; Prognostic factors