Diagnosis of thyroid carcinoma by ultrasonic examination: comparison with diagnosis by fine needle aspiration cytology.

Ultrasonic examination was performed on 120 patients who later underwent surgery. Ultrasonically, among the 64 cases of benign nodules and the 56 of carcinomas, 50 and 46 cases respectively were diagnosed correctly. In making the ultrasonic diagnosis, the following findings were considered; shape, margin, boundary, internal echoes, hyperechoic spots, the echo level of the nodule and the cystic pattern. The sensitivity for carcinoma diagnosis was 0.82, specificity was 0.78 and accuracy was 0.80. The diagnostic accuracy for the same patients using a newly devised diagnostic system that utilized a fuzzy inference was almost as high as that of the conventional method. Furthermore, the diagnostic accuracy of both of these methods did not differ significantly from that obtained by fine needle aspiration cytology. Therefore, non invasive ultrasonic examination is considered to be very useful for the detection and diagnosis of thyroid carcinoma.