Ultrasound Elastography in Differential Diagnosis of Benign and Malignant Thyroid Nodules / 대한내분비외과학회지

ABSTRACT

PURPOSE: The study evaluated elastography, a technique that allows differentiation between pathological and normal tissue by determination of tissue hardness. METHODS: From March 2009 to April 2010, 25 consecutive patients with thyroid nodules who were referred for surgical treatment were examined in this prospective study. Thirty nodules in these patients were examined by conventional ultrasound, ultrasound elastography, and fine needle aspiration cytology. Lesions were scored (1~3) according to hardness based on the Ueno classification system. The final diagnosis was based on histopathologic results. RESULTS: Of the 30 thyroid nodules, four were classified as benign and 26 were malignant. Two of the nodules with an elastography score of 1 were benign and 17 nodules whose elastography score was 3 were malignant. Two benign nodules and nine malignant nodules had an elastography score of 2. Applying an elastography score exceeding 2 as a indicator for malignancy determined that the sensitivity and specificity of the ultrasound elastography was 100.0% and 50.0%, respectively, the positive and negativepredictive values were 92.9% and 100.0%, respectively, and the accuracy of the technique was 93.3%. CONCLUSION: Ultrasound elastography may be a useful adjunct to ultrasonography in the identification of indeterminate thyroid nodules for which tissue diagnosis is required.