Abstract:Objective To investigate the value of superb microvascular imaging (SMI) combined with high-frequency ultrasound in the diagnosis of benign and malignant thyroid nodules in diffuse thyroid disease.Methods A total of 121 patients with thyroid nodules and diffuse thyroid disease who were admitted to the hospital from January 2020 to December 2021 were selected for the prospective study. All patients underwent SMI and high-frequency ultrasound scan, and pathological diagnosis was used as the gold standard.Results The clinicopathological findings of the 121 patients showed that 38 of them had malignant thyroid nodules and 83 had benign thyroid nodules. The SMI diagnosed 51 malignant thyroid nodules and 70 benign thyroid nodules, while the high-frequency ultrasound diagnosed 53 malignant thyroid nodules and 68 benign thyroid nodules. The scores of composition, echogenicity, shape, margin, echogenic foci of the thyroid nodules as assessed via the Thyroid Imaging-Reporting and Data System (TI-RADS) in malignant nodule group were all higher than those in benign nodule group (P < 0.05). The receiver operating characteristic (ROC) curve analysis showed that the sensitivities of SMI, high-frequency ultrasound and their combination in diagnosing benign and malignant thyroid nodules in diffuse thyroid disease were 81.58% (95% CI: 0.651, 0.917), 78.95% (95% CI: 0.621, 0.899), and 94.74% (95% CI: 0.809, 0.991). The specificities were 75.90% (95% CI: 0.650, 0.843), 72.29% (95% CI: 0.612, 0.813), and 98.80% (95% CI: 0.925, 0.999). The areas under the ROC curves (AUCs) were 0.922 (95% CI: 0.873, 0.970), 0.910 (95% CI: 0.857, 0.962), and 0.987 (95% CI: 0.957, 1.000).Conclusions SMI combined with high-frequency ultrasound increases the diagnostic performance for benign and malignant thyroid nodules in diffuse thyroid disease.