Partially cystic thyroid cancer on conventional and elastographic ultrasound: a retrospective study and a machine learning-assisted system.

BACKGROUND: Thyroid carcinoma constitutes the vast majority of all thyroid cancer, most of which is the solid nodule type. No previous studies have examined combining both conventional and elastic sonography to evaluate the diagnostic performance of partially cystic thyroid cancer (PCTC). This retrospective study was designed to evaluate differentiation of PCTC from benign partially cystic nodules with a machine learning-assisted system based on ultrasound (US) and elastography. METHODS: Patients with suspicious partially cystic nodules and finally confirmed were included in the study. We performed conventional US and real-time elastography (RTE). The US features of nodules were recorded. The data set was entered into 6 machine-learning algorithms. Sensitivity, specificity, accuracy, and area under the curve (AUC) were calculated. RESULTS: A total of 177 nodules were included in this study. Among these nodules, 81 were malignant and 96 were benign. Wreath-shaped feature, micro-calcification, and strain ratio (SR) value were the most important imaging features in differential diagnosis. The random forest classifier was the best diagnostic model. CONCLUSIONS: US features of PCTC exhibited unique characteristics. Wreath-shaped partially cystic nodules, especially with the appearance of micro-calcifications and larger SR value, are more likely to be malignant. The random forest classifier might be useful to diagnose PCTC.

[The perfusion pattern of lymphadenopathy in contrast-enhanced ultrasonograph. under different reference conditions ].

OBJECTIVE: To determine the perfusion pattern of lymphadenopathy in contrast-enhanced ultrasonography (CEUS) under different reference conditions. METHODS: The CEUS perfusion patterns of 78 superficial lymph node lesions were compared with their pathology results. Time-intensity curves were used for comparison between benign and malignant lymph nodes. RESULTS: Inhomogeneous hyperenhancement was the main perfusion pattern (7/17, 41. 2%) in metastatic lymph nodes; compared with homogeneous hyperenhancement (2/4, 50. 0%) in lymphoma, homogeneous hyperenhancement and isoenhancement (6/52, 11. 5%) in reactive lymph nodes, and circle enhancement (2/4,50. 0%) in tuberculosis. Benign lymph nodes showed different mean value, peak intensity and area under the curve compared with their surrounding arteries (P<0. 05). But the differences in mean value, rise time, time to peak, peak intensity and the area under the curve between benign lymphadenopathy and their surrounding tissues were not statistically significant (P>0. 05). Malignant lymph nodes showed different mean value and peak intensity compared with their surrounding arteries and tissues (P<0. 05). The differences in time to peak between malignant lymph nodes and their surrounding tissues were also statistically significant (P< 0. 05). CONCLUSION: Different CEUS perfusion patterns are associated with different types of lymph node lesions. Time intensity curves with surrounding tissues as reference condition offer great values for the differential diagnosis of superficial lymphadenopathy.