High-frequency Ultrasound Feathers Of Papillary Thyroid Carcinoma: Different Diagnostic Value According To Nodule Size

Objective: To evaluate the diagnostic value of ultrasound feathers forpapillary thyroid carcinoma (PTC) according to nodule size, and find a betterway of diagnosing PTC in early stage.Materials and methods: We retrospectively examined207thyroidnodules in our hospital from September2011to February2013. Nodules weredivided into groups by size: small (≤0.5cm, group A), medium (0.5–1cm,group B), and large (＞1cm, group C). Sonographic features were defined asA/T＞1, microcalcifications, blurred margins, hypoechogenicity, and markedintrinsic hypervascularity(type III vascular flow). Compare the sensitivity、specificity、 positive predict value(PPV)、 negative predict value(NPV)anddiagnostic accuracy of these ultrasound feathers. Use the Receiver OperatingCharacteristic to analysis the diagnostic value of different ultrasoune feathersand different ways of the combination of these feathers according to nodulesize.Results:①PTC with A/T＞1were smaller(P<0.001) and meanwhile PTCwith microcalcification were larger(P<0.001). The benign nodules with blurredmargins were smaller(p=0.014). Both PTC and benign nodules withhypoechogenicity(P=0.009and P<0.001) were smaller and with type IIIvascular flow(P<0.001) were larger.②A/T＞1and microcalcification had high specificity(95.5%and92.8%),PPV (94.9%and87.0%)and diagnose accuracy(81.2%and87.0%) for all PTC.In the mean time, blurred margins and hypoechogenicity had high sensitivity(98.2%and93.5%). The type III vascular flow had a poor diagnostic value.③A/T＞1was the most accurate ultrasound feature for predicting PTC in small nodules with high sensitivity (81.4%) and specificity (96.8%), but itwas not accurate in large nodules (＞1cm).Microcalcifications showed a highersensitivity (P <0.05) in large nodules (60.0%) than in small ones (27.9%).Hypoechogenicity and blurred margins showed high sensitivities (95.3%and97.7%, respectively) but low specificities (19.4%and29.9%, respectively) inthe diagnosis of PTC in small thyroid nodules.④ROC analysis show that A/T＞1had a high diagnostic accurate in smallnodules(AUC=0.981， P<0.001), and a low diagnostic accurate in largenodules(AUC=0.632，P=0.118).⑤A/T＞1in conjunction with one other US feature achieved the highestdiagnostic accuracy in small nodules.Conclusions:①The predictive values of US features depend on nodulesize. A/T＞1, especially in conjunction with another sonographic risk factor,showed superior performance for PTC diagnosis in nodules≤1cm(especiallywhen nodules≤0.5cm).②A/T＞1has a high specificity but a low sensitivity and diagnosticaccuracy for PTC diagnosis in nodules＞1cm. the diagnostic value of otherthree feathers are in the medium level.③The pattern of vascular flow is not a good predict feather for PTC.