[Comments on the ultrasonographic evaluation of thyroid nodules].

Thyroid ultrasonography does not allow establishing a positive diagnosis as to the benign or malignant nature of a thyroid nodule. However, the predictive value of this technique should be studied on the basis of recent technological progress. The great power of resolution of current sonographic systems allows a fine semiological analysis of the features of nodules. Presumption factors such as the solid, hypoechogenic nature, predictive of cancer in 35 to 63% of cases according to series, can be gathered. Thus ultrasonography can be placed in its right place for decision in the diagnostic strategy for a cold nodule; this place is better than that of radionuclide scanning, and close to that of cytology. This technological progress involves an increase in the prevalence of thyroid nodules. Multiple infraclinical micronodules, visible on ultrasonography but with uncertain pathological significance, are demonstrated. While ultrasonography has a disputable predictive value in such cases, it still is the technique of choice for the surveillance of such nodules. Sonographic guidance of cytological puncture of thyroid nodules, doppler studies of nodule vasculature and computer-supported analysis of its texture are interesting capabilities that may allow increasing the diagnostic efficiency of thyroid ultrasonography.