Application of two dimensional ultrasound in the fine needle aspiration biopsy of thyroid nodules

Objective In this paper,we selected the ultrasound features of the malignant thyroid nodules to evaluate the preoperative diagnostic value of ultrasound-guided fine needle aspiration biopsy ( US-FNAB )in the preoperative evaluation of thyroid nodules.Methods Thirty-nine patients with thyroid nodules managed in the department of otolaryngology-head and neck surgery,Beijing Tongren Hospital,Captial Medical University from Dec.2010 to Aug.2011 were studied.All of them were undertaken the ultrasonic examination,ultrasound-guided fine needle aspiration biopsy and surgical treatment subsequently.The ultrasonic features,fine needle aspiration biopsy results and postoperative pathological results were analyzed to draw out the characteristics of sonographic features of thyroid malignant nodules.Results The sensitivity,specificity,misdiagnosis and missed diagnosis of fine needle aspiration biopsy were 80.0％,89.4％,11.0％ and 20.0％ respectively.Solid nodules,shape/dimension ratio ≥ 1,calcifications ＜ 2 mm,irregular shape,blurred margins,type Ⅲ vascularity were correlated significantly with the malignant nodules of thyroid.The specificity of shape to dimension ratio and outline of the nodules were relatively higher than others (90.5％and 85.7％ respectively).But there were no single ultrasound feature that could carry a high sensitivity and positive predictive value in the diagnosis of thyroid nodules.Conclusions Two ultrasonographic characteristics could be used together as a select indicator to screen malignant nodules which can reduce the chance of undertaking the fine needle aspiration biopsy in thyroid nodules. Key words: Thyroid;  Nodule;  Ultrasonography;  Fine needle aspiration biopsy