Ultrasonic elastography in differential diagnosis of benign and malignant small thyroid nodule
GAO Qing-mei;ZHANG Mei;Department of Ultrasound,the 88th Hospital of Chinese PLA;
Objective In order to explore the best diagnostic threshold of ultrasonic elastic strain ratio and analyse the clinical value of ultrasound elastography in differential diagnosis of benign and malignant small thyroid nodules. Methods The 129 patients with small thyroid nodules(total number:138),which were confirmed by pathology. Diameters of these nodules were less than 1cm. In this study HI Vision Preirus color Doppler ultrasonic diagnostic apparatus with linear array probe was adopted. The frequency was from 5 to 13 MHz. All the patients received conventional ultrasound,ultrasonic elastography for ultrasound elastography classification and strain ratio's measurement. All obtained data were processed by software SPSS 17.0. Using the statistical software,ROC curve was drawn. And the strain ratio's optimal threshold value in the differential diagnosis was obtained. The diagnostic value of the various methods were-analyzed. χ2test was adopted to compare the differences among the various diagnostic methods. P≤0.05 was defined as statistically significant difference. Results 1)The strain ratio's optimal threshold value was 3.635. The ratio of 3.635 or greater was malignant,while the ratio of less than 3.635 was benign; 2)Pairwise comparisons among the four methods of diagnosis,the strain ratio was more specific than conventional ultrasound combined with ultrasound elastography classification,the ultrasound elastography classification and conventional ultrasound combined with ultrasound elastography classification were more sensitive than conventional ultrasound,the difference had statistically significance(P0.05); 3)The area under the ROC curve of four differential diagnosis methods were compared. The strain ratio of the area under the curve was greater than0.9,showing that accuracy is high. The area under the ROC curve for the remaining three methods located at 0.7-0.9,showing that these three methods had a certain diagnostic accuracy for small thyroid nodules. Conclusion Ultrasound elastography has certain diagnostic value for small thyroid benign and malignant nodules.The ultrasound elastography classificationcan combination with the conventional ultrasound can improve the early detection rate of thyroid microcarcinoma.The strain ratio can semi-quantitatively reflect the hardness of the lesions. It is more objective than ultrasound elastography classification in judging the benign and malignant small thyroid nodules. But they are affected by many factors,so comprehensive judgment is required in the clinical application.
【CateGory Index】： R736.1;R445.1