[Diagnostic value of ultrasonography in thyroid lesions].

Objective: To analyse ultrasonographic mapping of the thyroid lesions, so as to summarize ultrasonographic characteristics, and improve the accuracy rate of preoperative diagnosis for thyroid lesions.

Methods: The clinical data were analyzed for 1700 patients with different thyroid lesions who were treated between January 2002 and December 2005. The appearance of gray scale and colour Doppler sonography for the lesions was prospectively studied, the different blood flow index was determined. All patients underwent surgery and had histopathologic diagnosis at Cancer Hospital, Chinese Academy of Medical Sciences. The criterion of diagnosis for benign lesions were (1) multinodular; (2) the presence of peripheral halo; (3) regular and defined margins, intranodular uniform echogenicity; (4) macrocalcification; (5) the degree of blood flow was I or IV grade, the distribution of blood flow was I type; (6) the blood resistance index was over 0. 6, the blood peak value speed was below 12 cm/s. The criterion of diagnosis for malignant lesions were (1) single nodular; (2) irregular and partly defined margins; (3) intranodular irregular hypoechogenicity; (4) microcalcification; (5) the degree of blood flow was II or III grade, the distribution of blood flow was II type; (6) the presence of metastatic lymph node in region; (7) the blood resistance index was below 0. 6, the blood peak value speed was over 12 cm/s.

Results: Of all cases, 1284 cases were benign and 416 cases malignant. The accuracy rate of gray scale sonography for benign and malignant thyroid lesions was respectively 80. 0% and 75.0%. The accuracy rate of ultrasound diagnosis for benign and malignant thyroid lesions was respectively 86.0% and 82.0%, total accuracy rate for thyroid lesion was 85.0%.

Conclusions: Gray scale sonography was very important to distinguishing between benign and malignant lesions of thyroid tumor, the accuracy rate was greatly improved with colour Doppler sonography, but the determination of blood flow index is no help to differentiating between benign and malignant lesions of thyroid tumor. The accurate rate of ultrasound for the diagnosis of thyroid lesions is high, it is the first choice measure in preoperative diagnosis for thyroid lesions.