Evaluation of the elastography in differentiating thyroid solid nodules

Abstract

Objective To summarize the characters of the elastograms of different pathological nodules, and to observe the value of elastography in differentiating benign from malignant thyroid solid nodules. Methods One hundred and sixteen patients with thyroid nodules were enrolled in the study and 122 nodules were detected in total. All of them were examined by elastography and conventional ultrasound. Five sonographers were invited to evaluate the nodules double blinded basing on the images and the four-point system proposed by Fukunari. The interobserver agreement was evaluated by Kappa coefficient. Diagnostic performances of the five readers were compared by the ROC curves. Distributions of elastography scores of different pathological nodules were compared by one-way ANOVA. Results Interobserver agreements on scoring the nodules were moderate. Mean value of benign nodules was obvious lower than that of the malignant ones. The mean score of nodular goiters was 2.67 ± 0.89, range from 1 to 3. Most of the adenomas got score of 2, but the score of thyroiditis was quite high. No significant differences were found between the comparison of thyroiditis and thyroid cancers. Areas under the ROC curve (AUC) of the five readers were 0.82,0.81,0.79,0.73 and 0.83 respectively. When 3.5 was choosen as the cut-off point, the sensitivity of elastography was 82.4%, and specificity was 71.6%. Conclusions Elastography was really a useful technique for it can provide a new index for the differential diagnosis of thyroid nodules. However, the 4-point score system is not comprehensive enough. Key words: Ultrasonography; Thyroid diseases; Elastography