Effect of combining ultrasonography and ultrasound-guided fine-needle aspiration biopsy findings for the diagnosis of thyroid nodules

Objective: To assess the accuracy of ultrasonography and cytology in predic ting malignancy in thyroid nodules. Design: Prospective open study. Setting: Thyroid centre, Japan. Subjects: 329 nodules in 309 patients exami ned by anew ultrasound scanner and ultrasound-guided fine-needle aspiration biopsy. Interventions: Comparison of ultras ono graphic, cytological, and combined diagnosis with the histological diagnosis. Main outcome measures: Sensitivity, specificity, and accuracy of each diagn ostic method. Results: The sensitivity, specificity, accuracy were 84%, 87%, 85% for cyto logical diagnosis, and 82%, 91%, and 87% for ultrasonographic diagnosis. By using ultrasonographic diagnosis when cytological specimens were inadequat e or gave false negative results, the sensitivity, specificity, and accurac y went up to 89%, 91%, and 90%, respectively. We could not diagnose follicu lar carcinomas accurately by combined cytology and ultrasonography. Conclusion: The combination of ultrasonography and cytology improves the ac curacy of diagnosis of thyroid nodules, but is less effective with follicul ar tumours.