Clinical Study Of Ultrasonogram Stratifying Characterization And Reporting System For Thyroid Nodules

Objective To investigate the value of grayscale ultrasound, Doppler ultrasound andvalue of elastography in differential diagnosis of benign and malignant thyroidnodules, and to develop and validate a convenient and practical thyroid imagingreporting and data system (TIRADS) with which to categorize thyroid nodules andstratify their malignant risk.Methods PartⅠ: Seven hundred eighty-five patients with1024thyroid noduleswere enrolled in this part. The nodule size between the benign and malignant thyroidnodules were analyzed by t-test; the mulifocality, ratio of the anteroposterior totransverse diameter A/T, margin, borders, halo, internal content, echogenecity,calcification, vascularity pattern, US elastography score, extracapsular extension,central cervical lymph nodes nodule metastasis were analyzed by the chi-squared testor Fisher exact probabilities; a score for each significant factor was assigned base onORs from multivariate logistic regression. The fitted probability from the regressionequation and malignancy rate of thyroid nodules in different levels of score wascalculated.PartⅡ: The total score of nodules were classified according to fitted probability andmalignancy rate. Then modifed the classification base on the literature and statisticalresults to develop an ultrasonogram stratifying characterization and reporting systemfor thyroid nodules: categories Ⅰ, benign; categoriesⅡ, probably benign; categoriesⅢA, low suspicion for malignancy; categories ⅢB, intermediate suspicion formalignancy; categories ⅢC, highly suggestive of malignancy, but uncertain;categoriesⅣ, consistent with malignancy. Then used this system toevaluate thenodules before surgery, and analyzed its diagnostic value.Results Part Ⅰ: Pure colloidal cyst and spongiform nodules were specificperformances of benign nodules. Presence of a "snowstorm" pattern of calcification,extracapsular extension and central cervical lymph nodes nodule metastasis were highly specific for malignancy. There was a certain correlation between malignancyand intranodular vascularity, hypoechogenicity, a spiculated or microlobulatedmargin, A/T＞1, irregular halo, diffused microcalcification and markedhypoechogenicity, and their ORs were2,7,8,11,16,58and72, respectively.PartⅡ: All nodules of categoriesⅠ in retrospective set were benign, and malignancyrates were increase with the level of categories. The malignancy rate of prospectiveset were similar to retrospective set, and there were no significant difference in thesetwo sets. The area under the receiver operating characteristic (ROC) curve ofretrospective set and prospective set were0.964and0.970, respectively.Conclusion The characterization and reporting system using suspicious malignantUS features and scores may be helpful in risk stratification of thyroid nodules.