Application of Strain Ratio on the Diagnosis of Thyroid Malignant Tumor Using Different Calculation Methods / 中国医学影像学杂志

ABSTRACT

PurposeThe restriction of strain ratio (SR) in the diagnosis of thyroid malignant tumor are caused mainly because of disadvantages including low sensitivity, in this research the authors used different calculation methods of strain ratio based on the size of tumors, to explore the clinical application value of them on the differentiation of benign and malignant thyroid nodules.Materials and Methods Data of 336 patients with thyroid nodule (340 nodules) who underwent elasticity imaging and ultrasound-guided fine-needle aspiration were retrospective analyzed, with the pathology combined follow up acted as golden standards, fixed surface area assay and true surface area assay of strain ratio were compared on the differential diagnosis of benign and malignant thyroid nodules with various size.Results Among 340 thyroid nodules, there were 91 small nodules and 249 big nodules. Pathological results showed that 36 of 91 small nodules and 104 of 249 big nodules were malignant, while the others were benign. The true surface area assay was significantly better for the diagnosis of smaller thyroid nodules with longitudinal diameter and transverse diameter8mm (χ2=57.08,P<0.01). The sensitivity, specificity and consistency for the diagnosis of malignant nodules of true surface area assay were 57.10%, 83.00% and 72.30% (Kappa=0.413), which were 73.60%, 85.00% and 72.30% (Kappa=0.590) in the fixed surface area assay, and 85.00%, 85.50% and 85.30% (Kappa=0.699) in the selective usage of two methods according to the tumor size, respectively.Conclusion The sensitivity is highest when using the two methods selectively according to the nodule size, with a better consistence rate with pathological results as well.