Diagnosis Value Of The Papillary Thyroid Microcarcinoma By Conventional Ultrasound And Contrast-enhanced Ultrasound

Objective: Compared with conventional ultrasound(US), color doppler flowimaging(CDFI), contrast-enhanced ultrasound(CEUS) and combined withconventional US, CDFI and CEUS, to evaluate the differential diagnosis value of theminimal benign and malignant lesion in thyroid respectively. Compared with thequalitative diagnosis and quantitative diagnosis of contrast-enhanced ultrasound(CEUS), to evaluate theirs diagnosis role of the minimal benign and malignant thyroidlesion.Methods: Inclusion criteria of102cases:①isolated low echo nodules in thyroid,②the thyroid parenchyma echo uniform,③the maximum diameter of a nodule≤10mm,④TI-RADS:3or4. Exclusion criteria:①the low echo nodules＞10mm indiameter,②the hyperechoic and isoecho nodules,③with multiple nodules,④itcannot display solid tissue of the nodules due to the bulky calcification in nodules,⑤there were not satisfied with materials in FNA diagnosis classification. All patientswere examined by Mylab90(Co. Esaote, Italy). The SonoVue (Co. Bracco, Italy) asthe contrast agents, were injected into bodies with1.0ml from the median cubital veinof patients by bolus method. The characteristics of CEUS in micronodules of thyroidwere observed with the naked eye, and the parameters data of CEUS were created bythe time-intensity curve (TIC) from using the Qontrast4.0software to make it. Andfinally statistical analysis was done with pathological results as the gold standard. Inorder to achieve unified standard, for the requirement of the operator, it wasimplemented by three fixed with contrast-enhanced ultrasound doctors experienceover3years. In the statistical methods, there used binary logistic regression analysisand ROC curve of diagnostic test, and for the area under the ROC curve for acomparative analysis.Results:1. Univariate analysis, in general conditions of patients, the papillarythyroid microcarcinoma with an average age(40.69±10.67) were less than the average age of the patients with benign group(49.52±13.21). Their age in malignant groupswere between the ages of30to50for the most part, the differences of the age wasstatistically significant between the minimal benign and malignant lesion groups ofthe thyroid（P<0.05）, the gender differences was not statistically significant betweenthe minimal benign and malignant lesion groups of the thyroid（P>0.05）. In US andCDFI, the main US and CDFI features of the papillary thyroid microcarcinoma wereirregular form, unclear boundaries, A/T≥1, micro-calcification in nodules, abnormalswelling lymph nodes in the neck, and the differences of the above5indicators werestatistically significant between the minimal benign and malignant lesion groups ofthe thyroid（P<0.05）. In qualitative analysis of CEUS, the main CEUS features of thepapillary thyroid microcarcinoma were slow flow-in, centrality of enhanced perfusion,enhanced inhomogeneous, low or secondary enhancement at peak time, lesionsenlarged after enhanced, not-clear display in boundary, not enhanced rim at the border.In addition to enhanced inhomogeneous, the differences of the above indicators werestatistically significant between the minimal benign and malignant lesion groups ofthe thyroid（P<0.05）. The result of the quantitative analysis from the time-intensitycurve of showing the differences were statistically significant between the minimalbenign and malignant lesion groups of the thyroid in PEAK, RBF, SImax, SImean, therelative PEAK, the relative TTP, the relative RBV, the relative RBF, the relativeSImax and the relative SImean(P<0.05).2. Multivariate analysis, in US, CDFI andgeneral conditions of patients, A/T, regular form or not, micro-calcification innodules and abnormal swelling lymph nodes or not in the neck were elected to themulti-factor regression equation. And the accuracy, sensitivity and specificity topredict the papillary thyroid microcarcinoma respectively were82.4%,80.0%,84.6%.In the indicators of the qualitative analysis of CEUS, perfusion pattern, enhanced rimor not at the border after enhanced were elected to the multi-factor regressionequation. And the accuracy, sensitivity and specificity to predict the papillary thyroidmicrocarcinoma respectively were87.3%,86.0%,88.5%. In the parameters of thequantitative analysis of CEUS, only the relative SImax was elected to the multi-factorregression equation. And the accuracy, sensitivity and specificity to predict thepapillary thyroid microcarcinoma respectively were66.7%,60.0%,73.1%. Combinedwith conventional US, CDFI and all of the indicators and parameters of thequantitative and the qualitative analysis of CEUS, A/T, micro-calcification in nodules, abnormal swelling lymph nodes or not in the neck, perfusion pattern, enhanced rim ornot at the border after enhanced and SImax were elected to the multi-factor regressionequation. And the accuracy, sensitivity and specificity to predict the papillary thyroidmicrocarcinoma respectively were93.1%,92.0%,94.2%.3. ROC curve analysis, takethe diagnostic method of conventional US, CDFI, the quantitative and the qualitativeanalysis of CEUS, and Combined with conventional US, CDFI and the quantitativeand the qualitative analysis of CEUS separately for ROC curve analysis, and thecorrespond receiver operator characteristic curves were90.0%,90.7%,99.0%. Thus itcan be seen that the diagnostic capability had been increased significantly by thecombination diagnostic method. With the diagnostic method of the qualitativeanalysis of CEUS and the quantitative analysis of CEUS separately for ROC curveanalysis, and the correspond receiver operator characteristic curves were90.7%,69.7%. Obviously drawn, comparing to the diagnostic method of the quantitativeanalysis of CEUS, the diagnostic method of the qualitative analysis of CEUS withmore advantages in diagnosis.Conclusions: Compared to the quantitative analysis of CEUS to identify thepapillary thyroid microcarcinoma, it is more accuracy, sensitivity and specificity bythe qualitative analysis of CEUS. Combined with conventional US, CDFI and all ofthe indicators and parameters of the quantitative and the qualitative analysis of CEUS,the differential diagnosis of the minimal benign and malignant thyroid nodules, whichaccuracy is increased apparently. It is worth popularizing in clinic.