The Application Of Strain Ratio For Ultrasonic Elastography In Diagnosis Of Benign And Malignant Thyroid Nodules

Objective To evaluate the clinical value of elasticity score and strain ratio on ultrasonography in the differential diagnosis of thyroid nodules and the cut-off point of strain ratio for thyroid nodules.Methods Elasticity imaging was used to examine 64 patients with 91 thyroid nodules. The elasticity scores and strain ratio were retrospectively reviewed and compared with pathology. The elasticity grades 0-Ⅱwas predict of benign, gradesⅢ-Ⅳwas predict of malignant.Results (1) An elasticity score of 0-Ⅱwas observed in 45 of 91 nodules in 45 cases, while a score ofⅢ-Ⅳin the rest 46 nodules. An elasticity score of 0-Ⅱwas observed in 43 of 64 benign nodules, while a score ofⅢ-Ⅳin 25 of 27 malignant nodules; Elasticity score 0-Ⅱwere observed in the majority of benign nodules, while scoreⅢ-Ⅳin the majority of malignant nodules; (2)67 nodules＜5.525,24 nodules≥5.525 in elastic strain ratio.The mean of elastic strain ratio 7.38±3.72 was statistically higher in 27 malignant nodules than 2.61±1.32 in 64 benign nodules (P＜0.05); (3) According to ROC analysis,the cut off point of strain ratio was determined as 5.525, Youden's index was 0.78,62 nodules with elastic strain ratio<5.525 were confirmed as benign by pathology,22 nodules with elastic strain ratio≥5.525 were confirmed as malignant by pathology, sensitivity was 81.5% and specificity was 96.8%; (4) The diagnostic accuracy of the strain ratio was superior to that of elasticity score.Conclusions 1.The elasticity score in elasticity images are helpful in the differential diagnosis of thyroid lesions.2. The mean of elastic strain ratio is statistically higher in malignant nodules than that of in benign nodules, the cut off point of strain ratio is determined as 5.525.3.The hardness of nodules is determined by pathological features,the strain ratio can objectively reflect the hardness of nodules. Malignant nodules are harder than benign nodules, meanwhile the SR of malignant nodules are higher than that of in benign nodules.4.The diagnostic accuracy of the strain ratio is superior to that of elasticity score,and they are both have an accuracy in the diagnostic of thyroid nodules.