ABSTRACT
Objective To select sonogram features for the differential diagnosis of benign and malignant thyroid small nodules by Logistics regression analysis,and to contribute the binary Logistic regression model of sonogram features as independent variable and evaluate the value of conventional ultrasonography and ultrasound elastography (UE) in the differential diagnosis of benign and malignant thyroid small nodules.Methods 166 thyroid nodules (≤ 10 mm) in 140 patients were reviewed and analyzed by 2D ultrasound,color Doppler flow imaging and UE.A Logistic model was obtained based on pathology as golden diagnosis criteria.The odds ratio of variables in the equation were compared to assess various variables,especially the efficacy of elastography in the diagnosis.Results Four statistically significant features were finally entering the Logistic stepwise regression model,including shape,calcification,the internal component of nodules and elasticity score.And the odds ratio of the elasticity score was higher than other features.Conclusions The analysis of binary Logistic regression can select the valuable variables for the diagnosis of pathological nature of thyroid small nodules.UE has much more dominances than other features.The combinated application of UE and 2D ultrasonic features plays a great clinical role in the final diagnosis of thyroid small nodules.
ABSTRACT
Objective To evaluate and screen out the specific characters of thyroid nodules on grayscale and color Doppler ultrasonography. Methods One hundred and four thyroid nodules in 95 patients were studied with gray-scale and color Doppler ultrasound before surgery.According to the probability of malignancy,the main independent characters were screened out by Logistic regression analysis and then got the formula which could calculate the probability of malignancy.Results Fifty three nodules,included 44 hyperplasia,7 adenomas,1 switch granuloma and 1 Hashimoto's disease,were benign.Fifty one nodules,included 47 papillary carcinomas,3 medullary carcinomas,1 metastatic carcinomas,were malignant pathologically.The significant characters to differentiate malignant from benign were the shape,margin,border,halo,echostucture,echogenecity,echo uniformity,calcicum,bolood vessel shape and partial abnormal rich blood of thyroid nodules.After two variables logistic regression analysis,a fomula were worked out.Probability of malignancy=1/1+e-z,which z=-7.44+1.30×halo+1.05×calcicum+1.5×vessel shape.If a thyroid nodule with no halo,microcalcicum and irregular vessel shape,the probability of malignancy was 0.99,while with complete halo,no calcicum and regular vessele shape,the probability of malignancy of the nodule was 0.02.Conclusions The halo,calcium and blood vessel shape of thyroid nodules were three independent characters of thyroid nodules to predict malignant thyroid nodules on gray scale and color Doppler ultrasound.