Value Of Elastography And TI-RADS Evaluation Standards In Differential Diagnosis Of Thyroid Nodules

ObjectiveTo evaluate the value of ultrasonic elastography (ultrasonic elastography, UE) elastic evaluation method and strain ratio (strain ratio, SR) combined with TI-RADS in diagnosing benign and malignant solid nodules of thyroid, then to provide reliable reference value in clinical treatment and makes it possible in early detection and early cure of cancer.Methods254 patients with thyroid nodules were selected, among them there were 309 lesions in total (205 benign and 104 malignant).We divides the patients into two groups by a nodule maximum diameter of 10 mm to conduct UE and the conventional examination. All the lesions were graded in accordance with TI-RADS and confirmed by the pathological gold standard. We builded the receivers operating characteristic curve (ROC curve). Lastly, we compared the difference of the TI-RADS evaluation standard and the UE elastic evaluation method with strain ratio in diagnosing thyroid nodules.ResultThe SR of malignant group was much higher than that of the benign, and the difference was statistically significant (t= 7.69, P<0.05). The sensitivity, specificity and accuracy of UE elastic evaluation method and strain ratio were 85.67%、89.85%、86.70% and 87.41%、91.21%、90.01%, and the sensitivity, specificity and accuracy of TI-RADS evaluation standard were 70.56%,83.49% and 80.08%. Ultrasonic elastography in diagnosing thyroid benign and malignant nodules was much more sensitive, specific and accurate than the method of TI-RADS evaluation standard, and the difference was statistically significant (P<0.05). What’s more, after the two methods combined, the sensitivity, specificity, and accuracy improved to 90.44%, 93.21% and 92.46%, which were higher than either single screening method. The areas under the UE strain ratio and TI-RADS evaluation standard diagnostic criteria curves were 0.82 and 0.76, the difference was statistically significant (P<0.01); and areas under the curve combined with two methods was 0.86, This means that the diagnostic value was higher than a single method (P< 0.01). In the group of nodule diameter≤10mm, the diagnostic accuracy of UE strain ratio was higher than that in TI-RADS evaluation standard (P<0.05), while in the group of nodule diameter>10mm, TI-RADS evaluation standard diagnostic accuracy was higher than the SR(P<0.05). Thyroid’s benign and malignant nodules shape, boundary, edge, the rear of the echo, vertical orientation, microcalcification, blood flow distribution and the lymphatic metastasis were statistically significant (P< 0.01).ConclusionUltrasonic elastography was much more accurate than TI-RADS evaluation standard in the diagnosis of thyroid benign or malignant nodules. And both methods could play complementary roles in diagnosing of different sizes of nodules, so a combination of these two methods could improve the accordance rate in diagnosing of thyroid benign and malignant nodules. Edge blur, boundary not clear, irregular shape, aspect ratio>1, posterior attenuation, blood flow disorder and microcalcification etc. can act as signs of turning thyroid nodules into malignant. Among them, In the group of nodule diameter≤10mm, aspect ratio>1 can be used as the major indicator to predict malignant tumor; nodules which diameter>10mm, irregular shape, edge blur, boundary not clear, microcalcification, blood flow disorders and the lymphatic metastasis can be used as the major indicator to predict malignant tumor.