Ultrasound Super-Resolution Imaging for the Differentiation of Thyroid Nodules: A Feasibility Study

Super-resolution imaging technique has shown the capability to break the diffraction limit of ultrasound to image microvessels. The purpose of this study was to assess its feasibility and value in the differentiation of thyroid nodules. In this study, 24 cases of thyroid nodules were examined by B-mode, color Doppler flow imaging and contrast-enhanced ultrasound. Super-resolution imaging was conducted to depict the microvasculature with finer details. Microvascular flow rate (MFR) as well as micro-vessel density (MVD) in thyroid nodules were calculated. MFR and MVD were used to distinguish benign from malignant thyroid nodules. Pathological results were considered as the gold standard. Our findings demonstrated that SRI could visualize human thyroid nodule microvessels in finer details and obtain useful clinical information, such as MVD and MFR to aid in differential diagnosis. The results showed that the mean MFR of benign thyroid nodules was 16.76 ± 6.82 mm/s, while the mean MFR of malignant thyroid nodules was 9.86 ± 4.54 mm/s. The mean value of MVD in benign thyroid nodules was 0.78, while that in the malignant thyroid nodules was 0.59. MFR and MVD in the benign thyroid nodules were significantly higher than those in malignant thyroid nodules (p < 0.01). This study demonstrated the feasibility of ultrasound super-resolution imaging to visualize the microvessels of human thyroid nodules. Important imaging markers, such as MVD and MFR, can be obtained from SRI to provide more useful clinical information. It showed a great potential to be a new method to aid in the differential diagnosis of thyroid nodules.