[Review of the current value of ultrasonography in the characterization of thyroid nodules]

Usefulness of semiquantitative elastography in predicting malignancy in thyroid nodules

OBJECTIVE

To retrospectively review the diagnostic capacity of semiquantitative elastography in differentiating between benign and malignant thyroid nodules.

PATIENTS AND METHODS

We analyzed 314 thyroid nodules in 295 consecutive patients referred to the endocrinology department for cytological study, studying all by conventional ultrasonography, elastography, and fine-needle aspiration cytology (FNAC). Using a semiquantitative elastography system that portrays tissue stiffness through a color map, we designed our own classification system for thyroid nodules based on their characteristics on elastography. We classified nodules into three groups: predominantly soft, predominantly stiff, and mosaic patterned. We used logistic regression analysis to investigate the relation between elastography and thyroid cancer.

RESULTS

We obtained a definite diagnosis of malignancy after surgery in 19 nodules, of which on elastography 8 had the mosaic pattern, 6 were predominantly stiff, and 5 were predominantly soft. We found no significant association between the pattern on elastography and the probability of malignancy in any of the models.

CONCLUSION

According to our study, la probability of malignancy in a thyroid nodule is not related to the findings at elastography. Therefore, semiquantitative elastography as used in this study cannot obviate FNAC.

Gray-scale vs. color doppler ultrasound in cold thyroid nodules

We intended to compare gray-scale vs. color Doppler ultrasound findings in cold thyroid nodules. Sixty-four patients with cold thyroid nodules for whom the presumptive diagnosis of malignancy (based on isotope scan study) had been made were consecutively included. They underwent gray-scale and color Doppler sonography studies. Based on histopathologic examination of surgically removed nodules, there were respectively 25 (39%) and 39 (61%) malignant and benign nodules. On color Doppler sonography, preference central hypervascularity was the most common finding in malignant nodules (17 nodules, 68%). Among benign nodules, preference perinodular hypervascularity was the most common finding (26 nodules, 66.7%). The most sensitive and specific Doppler sonography findings for malignant nodules were preference central hypervascularity (68%) and only central vascularity (97%), respectively. On gray-scale sonography, absent halo sign was the most common finding in malignant nodules (20 nodules, 80%). Among benign nodules, microcalcification was the most common finding which was reported in 12 nodules (30.7%). Hypoechogenicity was the most specific finding (76.9%) for malignant nodules. Since both gray-scale and color Doppler ultrasonography are inexpensive, non-invasive, and accessible methods to diagnose thyroid malignant cold nodules, it is recommended that these methods be applied by clinicians to assist or even substitute other invasive methods.