The Value Of High Frequency Ultrasound And Contrast-enhanced Ultrasound In Diagnosis Of Papillary Thyroid Micro-carcinoma And Its Invasive Nature

Objective: To investigate the diagnostic characteristics of high frequency ultrasound and contrast-enhanced ultrasound(CEUS)for papillary thyroid micro-carcinoma(PTMC)and its invasiveness predictive value and the related factors of cervical lymph node metastasis in patients with PTMC.Methods: The medical records of 81 patients with thyroid nodules who received surgical treatment were analyzed.All patients received high frequency ultrasound and CEUS examination before surgery,and the characteristics of nodules such as morphology,boundary,echo and enhancement intensity were observed and recorded.According to the pathological results,the patients were divided into benign group and malignant group,and the sonogram characteristics were compared according to the groups.In addition to observing the characteristics of high frequency ultrasound and CEUS of nodules in the malignant group,the relationship between nodules and thyroid capsule was mainly observed to calculate the diagnostic efficacy of invasive PTMC.195 PTMC nodules of 174 patients were divided into metastatic group and non-metastatic group according to the pathological results with or without cervical lymph node metastasis.The correlation between clinical and ultrasonographic characteristics and cervical lymph node metastasis was analyzed by means of the test of ?2 and multi-factor Logistic regression.Results:(1)Among the 81 nodules confirmed by surgery and pathology,the ultrasonic characteristics of the two groups showed that the ratio of aspect ratio ?1 and the proportion of micro-calcification in the malignant group were significantly higher than those in the benign group(66.7% vs.25.0%,54.4% vs.29.2%),with statistically significant differences(P<0.05).(2)The comparison of CEUS characteristics between the two groups showed that the proportion of the three characteristics of non-uniform enhancement,low enhancement and early significant regression in the malignant group was higher than that in the benign group,and the difference was statistically significant(P<0.05);(3)CEUS based on high frequency ultrasound inferred that PTMC was invasive with a sensitivity of 94.40%,a specificity of 87.20%,an accuracy of 89.47%,a positive prediction value of 77.27%,and a negative prediction value of 97.14%.(4)Cases which age<45 years,man and multifocality were seen more frequently in metastatic group compared with non-metastatic group(P<0.05);(5)Tumor size>7mm,the lesions were located at the upper and lower poles and isthmus of thyroid,and capsular inconnection were seen more frequently in metastatic group compared with non-metastatic group(P<0.05);(6)Multiple factor regression analysis showed that sex,age,single/multiple,capsular inconnection were the risk factors for cervical lymph node metastasis(P<0.05).Conclusion:(1)PTMC was diagnosed by CEUS with characteristic manifestations,CEUS has high diagnostic value in determining tumor invasion ability;(2)The clinical and sonographic character of papillary thyroid micro-carcinoma had some correlation with the occurrence of cervical lymph node metastasis,which can provide reference for clinical treatment.