Extra-Thyroid Extension Prediction by Ultrasound Quantitative Method Based on Thyroid Capsule Response Evaluation.

BACKGROUND The aim of this study was to assess the interaction between thyroid malignancies and thyroid anterior capsule by ultrasound quantification to determine extra-capsular invasion. MATERIAL AND METHODS A total of 145 patients preoperatively diagnosed with malignant nodules under the thyroid anterior capsule were selected and routinely examined by ultrasound. The length of the nodules (from the junction of the nodule capsule to the deepest point of the nodule, vertical diameter, V) and the distance between the nodule protruding from thyroid capsule and the highest protruding (ledge length, L) nodule were used to obtain the L/V ratio. These parameters where then used to compare the efficacy of predicting extra-thyroid extension (ETE) between L/V, the aspect ratio of the tumor, and manual judgment. RESULTS Out of 145 nodules, there were 63 ETEs and 82 non-ETEs determined by ultrasound. Extra-capsular invasion was associated with L//V ratio, but there was no significant correlation between capsular invasion and AR (aspect ratio), age, location, or presence of clustered calcification. The ability of the ratio of L/V to predict extra-capsular invasion was superior to the predictive ability of the AR ratio. With a Youden index of 0.593, the L/V ratio was 0.2325. The use of the L/V ratio to determine the presence of ETE was superior to subjective visual judgment. CONCLUSIONS The calculation of L/V ratio by ultrasound could more precisely predict the ETE compared with manual judgment, which indirectly reflects the interaction between thyroid capsule and malignant nodules. The above conclusions need to be confirmed by a range of cases.

Ultrasonographic evaluation of extracapsular vascular invasion for subcapsular nodules of the thyroid.

BACKGROUND: Ultrasound provides a high-frequency spatial resolution. In this study, we used the combined pathological features of extrathyroid extension (ETE) measured by ultrasound to evaluate the vascular manifestations of subcapsular differentiated thyroid cancer. Our study aims to explore the value of high-frequency ultrasonography in the evaluation of extracapsular vascular invasion for the evaluation of both benign and malignant nodules and the prediction of ETE. METHODS: A total of 167 thyroid nodules were enrolled in this study. High-frequency ultrasonography was used to observe the relationship between the blood flow of the nodules and the capsules. The blood flow was divided into two types according to the relationship: non-extracapsular invasive blood flow and extracapsular invasive blood flow. Non-extracapsular blood flow was defined as any flow seen inside or around the nodule that did not extend beyond the thyroid gland. Extracapsular invasive blood flow was defined as any blood flow seen inside or around the nodule that flowed across the capsule and extended beyond the thyroid gland. A comparison of the different types of blood flow to judge the nature of thyroid nodules for predicting ETE was performed. RESULTS: Out of 167 nodules, 81 cases of nodules were the non-extracapsular invasive blood flow type, while the remaining 86 cases of nodules were classified as the extracapsular invasive blood flow type. Nodules with distinct types of blood flow were significantly different in malignancy rates between the nodules (P<0.001). The incidence rate of ETE was also significantly different between the malignant nodules with distinct types of blood flows. CONCLUSIONS: Extracapsular vascular invasion is a good indicator for the evaluation of benign and malignant nodules. Using it as an indicator provides physicians with a potential tool for the prediction of ETE.