Incidentally discovered thyroid nodules: incidence, grey-scale and color Doppler pattern in an adult population screened by real-time compound spatial sonography

Purpose. Our aim was to assess the incidence and ultrasound features of thyroid nodules in an adult population screened by means of high-resolution ultrasonography (HRUS) and to evaluate the contribution of real-time spatial compound sonography (CS) in terms of image quality. Materials and methods. A total of 704 consecutive patients (400 women, 304 men) without thyroid disease underwent HRUS and CS examination of the thyroid gland. Number, size, location, echotexture and colour Doppler pattern of detected nodules were assessed. Two radiologists also assessed image quality of the two techniques. Results. Seven hundred and eleven thyroid nodules (size range 0.18-4.1 cm; mean: 1.1 cm) were detected in 233 subjects (33.1%). Of these, 416 (58.5%) were found in 143 women whereas 295 (41.5%) were detected in 90 men. In both genders, the number of detected nodules increased with age, with the highest prevalence in the seventh decade (p<0.001). There were 461/711 (64.9%) thyroid nodules that were hypoechoic, and 449/711 (63.1%) had peripheral vascularity only (p<0.001). Fine-needle aspiration (FNA) revealed no malignancies. CS was graded better than HRUS in 621/711 (87.3%) cases (p<0.001). Conclusions. The prevalence of benign, small, hypoechoic thyroid nodules with peripheral vascularity was high in our series, thus suggesting a conservative approach. CS provided better image quality compared with HRUS.