Differentiation of benign, intermediate, and malignant soft-tissue tumours by using multiple diffusion-weighted imaging models

Abstract

AIM

The aim of this study was to determine whether intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) can differentiate benign, intermediate, and malignant soft-tissue tumours (STTs) of the extremities and trunk.

MATERIALS AND METHODS

We prospectively recruited 100 STT patients (32, 15, and 53 patients with benign, intermediate, and malignant tumours, respectively). The patients underwent IVIM and DKI, and the following parameters were measured: standard apparent diffusion coefficient (ADC), perfusion fraction (f), true diffusion coefficient (D_slow), pseudo-diffusion coefficient (D_fast), water diffusion heterogeneity index (α), distributed diffusion coefficient (DDC), mean diffusivity (MD), and mean kurtosis (MK). Statistical analyses were performed using receiver operating characteristic curves, the Kruskal-Wallis H test, and post hoc test with Bonferroni correction.

RESULTS

Standard ADC, D_slow, DDC, and MD values gradually decreased from benign to intermediate and malignant STTs. Intermediate STTs displayed a lower f value than benign tumours (P=0.029). The MK value was higher in malignant tumours than in intermediate and benign tumours (P=0.021 and <0.001, respectively). The DDC value best differentiated benign tumours from nonbenign (intermediate and malignant) tumours (area under the curve [AUC] = 0.884, 0853, and 0.892, respectively). The optimal MK cut-off value for differentiating intermediate and malignant tumours was 0.65 (sensitivity: 73.33%, specificity: 81.13%, accuracy: 79.41%).

CONCLUSION

IVIM and DKI parameters were helpful for differentiating benign, intermediate, and malignant STTs and can complement conventional MRI, with DDC and MK values showing high diagnostic efficacy.