ObjectiveTo investigate the diagnostic value of conventional ultrasound and contrast-enhanced ultrasound for TI-RADS 4 shrunken thyroid nodules.

MethodsA tatal of 78 patients(80 nodules diagnosed as TI-RADS 4) undergoing conventional ultrasound and contrast enhanced ultrasound were selected and divided into the shrinkage nodule group(n=38, 38 nodules) and the papillary carcinoma group(n=40, 42 nodules) according to pathological results. Conventional ultrasound and contrast-enhanced ultrasound examinations were performed on all patients. The radiological characteristics of conventional ultrasound images and the enhancement modes of contrast-enhanced ultrasound were compared respectively.

ResultsIn terms of conventional ultrasound image features, there was no statistical significance in boundary, echo, aspect ratio, and calcification type(P>0.05), but statistical significance was found in calcification location and "halo sign"(P < 0.01) between the two groups. The incidence of marginal calcification, halo sign, no enhancement or low enhancement at stellate point in the shrinkage nodule group was higher than that in the papillary carcinoma group(P < 0.01). Shrinkage nodules mainly showed no enhancement or punctate low enhancement, while papillary carcinoma mainly showed centripetal low enhancement.

ConclusionsThe position of calcification of the nodule, the presence or absence of "halo sign" and the characteristic manifestations of contrast-enhanced ultrasound can distinguish thyroid shrinkage nodules and papillary carcinoma. Conventional ultrasound and contrast-enhanced ultrasound are significant in distinguishing thyroid shrinkage nodules and thyroid papillary carcinoma.