RESUMO
Objective To summarize the sonographic characteristics of high frequency ultrasound and elastography of thyroid microcarcinoma(TMC),and to analyze the causes of misdiagnosis.Methods The preoperative ultrasonic data of 245 suspicious TMCs in 202 patients,as confirmed by operation pathology,were retrospectively analyzed.Results Preoperative ultrasonography accurately diagnosed 221 TMCs,the diagnosis rate was 90.2％,and the misdiagnosis rate was 9.8％.Among the missed diagnosed lesions,18 lesions were nodular goiter,others were 3 nodular goiter with focal papillary hyperplasia of follicular epithelium,2 nodular goiter with adenomatous hyperplasia,1 focal lymphocytic thyroiditis,respectively.The thyroid lesions≤0.5 cm in diameter were more easily to misdiagnose.According to the importance of the ultrasonographic features of TMC,the order were aspect ratio (A/T) ≥ 1,irregular-shape,microcalcifications,low or very-low echo.Based on the above corresponding characteristics and considering other features together,the diagnostic accuracy rate were 94.1 ％,93.9％,92.4％ and 90.5％,respectively.Less blood supply and ill-defined boundary were the secondary sonographic signs of TMC.The elastographic scores of TMC were most showed 4 to 5 points.Diagnosis of TMC relied on elastography alone is less effective,but when elastograph diagnosis based on high frequency ultrasound,the diagnostic accuracy is much higher,especially when there is no calcification in the lesions.Conclusions High-frequency ultrasound has a very important value in the diagnosis of TMC,while elastography has certain assistant value on the basis of high-frequency ultrasonic diagnosis.
RESUMO
Objective To investigate the evaluation of virtual touch tissue quantification(VTQ)in differential diagnosis of thyroid benign and malignant nodules and its influence factors.Methods 127 patients with thyroid lesions and its adjacent normal thyroid tissue at the same depth were examined with VTQ.Test results were performed by shear wave velocity value (SWV) on the long axis dimension of the nodules.The maximum(Vmax),minimum(Vmin) value of SWV of thyroid lesions and the SWV(Vn) value of surrounding normal tissue were recorded.The mean value of SWV (Vm) and the ratio of Vm and Vn (Vm/n) were calculated.SWV value of benign and malignant nodules and different pathological types of nodules were analyzed.Receiver-operating characteristic curve(ROC) was drawn to assess the diagnostic efficiency.Results The Vmax,Vmin,Vm,Vm/n of malignant lesions [(4.61 ± 2.65) m/s,(2.74 ± 2.23) m/s,(2.99 ± 0.82)m/s,(1.69 ± 1.07)m/s,respectively] were obviously higher than that of benign nodules [(2.78 ± 0.96)m/s,(1.75 ± 0.60)m/s,(2.31 ± 0.38)m/s,(0.94 ± 0.23)m/s,respectively,P ＜0.01].The SWV value of thyroid papillary carcinoma was higher than that of nodular goiter,thyroid adenoma and Hashimoto's thyroiditis(P ＜0.05).The SWV value of Hashimoto's thyroiditis was higher than that of thyroid adenoma and nodular goiter (P ＜ 0.05).No significant differences of SWV value were found between thyroid adenoma and nodular goiter (P ＞ 0.05).Contrast the area under the receiver-operating curves above four groups of different SWV values,the results showed that Vm had the highest diagnostic value in diagnosis of benign and malignant thyroid nodules.When the best cut-off point of Vm was 2.48 m/s,the diagnostic value was highest and the sensitivity and specificity were 97％ and 81 ％.Conclusions VTQ could be used to quantify and evaluate the hardness of thyroid nodules and provided important value for the differential diagnosis of benign and malignant thyroid nodules.