Uitrasonic Elastography Evaluation Thyroid Nodules With Aspect Ratio More Than 1 The Value

Objective:Thyroid nodular disease is a common clinical disease, and the judgment of nodules directly affects clinical treatment. The present clinic diagnosis of thyroid nodule with aspect ratio more than 1 mainly relies on palpation, imaging examination and immunological determination etc. Thyroid nodules with aspect ratio greater than 1 are usually regarded as one of the markers of malignancy, but there is still a certain rate of misdiagnosis. As a new imaging model, ultrasound elasticity imaging can assess the elasticity of tissue(tissue hardness) to assist the differential diagnosis on thyroid nodules between benign and malignant. This study combined the advantages between two-dimensional ultrasound and elastography technology, aiming to identify their application value in benign and malignant nodules of thyroid aspect ratio more than 1.Methods: A retrospective analysis of patients with thyroid nodules, which were filtrated through routine ultrasound examination from October 2013 to March 2015 in our hospital outpatient or inpatient. Their thyroid aspect ratios are all more than 1 with clear image and completely clinical data. They all have conventional ultrasound, ultrasonic elasticity imaging and pathological detection results. Conventional ultrasound provided the records of nodule number, size, shape, boundary, internal echo, rear echo, acoustic halo, internal calcification, blood flow signal. The conventional ultrasound is classified according to TI-RADS. Thyroid nodules elasticity imaging analysis includes the detection of thyroid nodules hardness, storage of elastic graph while recording nodules the elasticity scores. The specificity, sensitivity and the accuracy of the combined diagnosis are evaluated by drawing the receiver operating characteristic(ROC).Results:A total of 95 patients, including 33 males and 62 females, have 102 thyroid nodules with the average aspect ratio of more than 1. The maximum diameter of nodules is 0.2 cm- 1.2 cm, 54 nodules in left thyroid lobe, and 41 nodules in right lobe, 7 nodules of isthmus. 102 thyroid nodules, according to histopathological study, were confirmed that 20 benign nodules contain 14 cases of limitation of Hashimoto’s thyroiditis, 3 cases of focal lymphocytic thyroiditis, 1 case of thyroid nodule fibrosis with necrosis and 2 cases of mesh shaped thyroiditis; 82 malignant nodules include 13 cases of papillary carcinoma, 68 cases of papillary microcarcinoma, 1 case of medullary thyroid carcinoma. The results of conventional ultrasound showed 79 low echo, 23 echo, 25 in regular shape, 77 in irregular shape, 27 with clear boundary, 75 with unclear boundary, 26 no calcification, 16 coarse calcification, 60 minute calcification, 29 surrounding acoustic halo, 73 surrounding silent halo, 39 rear attenuation, 72 rear attenuation, 14 enveloped, 88 non-enveloped, 29 no vessel, 28 simple edge type vessel, 19 vessel edge predominant, 26 mixed vascular type, 19 with size of nodules more than 1.0 cm and 83 less than 1.0cm. Conventional ultrasound diagnosis results: TI-RADS 3 grade 26, 4 grade 47, 5 grade 29; the sensitivity was 84.69%, specificity of 53.84%, accuracy rate of 82.35%. Elastography diagnosis results: 11 two grades, 17 three grades, 48 four grades, 26 five grades. The sensitivity is 82.56%, specificity is 42.85%, and accuracy is 76.47%. The result of conventional ultrasound combined with UE diagnosis: 7 five grades, 11 six grades, 30 eight grades, 24 nine grades, 13 ten grades. According to the sensitivity as ordinate, 1- specificity as abscissa, ROC curves were drawn as follows, two joint score 7 points with sensitivity 95.61%, corresponding to the optimal cutoff point, specificity 90.0% and accuracy 95.07%. So this study will be set to be greater than or equal to 7 points for malignant, while less than 7 points as benign.Conclusions:Compared with simple conventional ultrasound and pure UE, conventional ultrasound elasticity imaging technology possesses higher accuracy in the diagnosis of thyroid papillary carcinoma. Their combination can improve the discrimination between benign and malignant thyroid nodules, and reduce the rate of misdiagnosis.