The value of whole-lesion intravoxel incoherent motion diffusion weighted imaging based on turbo spin-echo sequence in differential diagnosis of thyroid benign and malignant nodules / 中华放射学杂志

ABSTRACT

Objective:To assess the diagnostic value of whole-lesion intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) in differentiating benign and malignant thyroid nodules based on turbo spin echo (TSE) sequence.Methods:Totally 57 patients with thyroid nodules diagnosed by pathology were prospectively collected at the Affiliated Lianyungang Hospital of Xuzhou Medical University from March 2019 to December 2019. A total of 62 nodules were included for analysis, including 27 benign nodules and 35 malignant nodules. All patients underwent routine MRI scan and IVIM-DWI based on TSE sequence before surgery. The regions of interest were drawn along the edge of the lesion on multiple consecutive slices to cover the entire nodule, and the apparent diffusion coefficient (ADC), diffusivity (D), pseudo-diffusivity (D *) and quantitation of perfusion fraction (f) values were measured, and the mean value of the multilayer measurement was recorded for further analysis. The differences of the parameters between benign and malignant thyroid nodules were analyzed using independent samples ttest (normal distribution) and Mann-Whitney U test (non-normal distribution). The diagnostic efficacy of parameters with statistical significance was evaluated using the receiver operating characteristics (ROC) curve. Results:The ADC, D and D *values in the malignant nodules were lower than those in benign nodules, the differences were statistically significant ( t=3.821, P=0.001; t=2.034, P=0.046).There were no statistical differences of D * and f values ( t=-1.170, P=0.247; Z=-0.559, P=0.577).The optimal cut-off values of ADC and D were 1.90×10 -3mm 2/s and 1.10×10 -3mm 2/s, with both sensitivity of 81.5%, specificity of 73.5% and 61.8%, respectively. The area under ROC curve of ADC and D were 0.782 and 0.688, and the statistical difference was found ( Z=2.098, P=0.040). Conclusion:The whole-lesion IVIM parameters (ADC and D) based on the TSE sequence provide imaging features for preoperative differentiation of benign and malignant nodules of the thyroid gland.