The association between hypoechogenicity or irregular echo pattern at thyroid ultrasonography and thyroid function in the general population

Abstract

Objective: Patients with overt hypothyroidism show decreased echogenicity of the thyroid at ultrasonography (US). The aim of this study was to investigate the association between echogenicity of the thyroid/irregular echo pattern, and thyroid function in the general population, i.e. subjects without overt thyroid disease. Design: A cross-sectional investigation of 4649 randomly selected adult subjects. Methods: Blood samples were analysed for serum TSH, thyroid hormones and thyroid autoantibodies. US of the thyroid was performed. Results: Participants with decreased echogenicity (nZ379) had a higher mean TSH (1.65 mU/l) compared with subjects with normal echogenicity (1.21 mU/l, P!0.0001). The association was stronger in subjects with markedly decreased echogenicity (4.20 mU/l, P!0.0001). A similar association was seen when the subjects were divided into subgroups according to the level of TSH; more subjects with high levels of TSH had decreased echogenicity (P!0.0001). Likewise, more subjects with high levels of TSH had an irregular echo pattern (P!0.0001). Subjects with decreased echogenicity had a higher risk of having thyroid autoantibodies than subjects without decreased echogenicity (P!0.0001). This association was stronger when echogenicity was markedly decreased. Conclusions: We demonstrated an association between hypoechogenicity at thyroid US and higher levels of serum TSH even in subjects without overt thyroid disease, suggesting decreased echogenicity as an early sign of thyroid dysfunction. Irregular echo pattern, whether accompanied by hypoechogenicity or not, was another possible marker of thyroid failure. This indicates a possible use of thyroid US in detecting early and subclinical thyroid dysfunction.European Journal of Endocrinology 155 547-552

Low concordance between positive antibodies to thyroperoxidase and thyroid ultrasound autoimmune pattern in pregnant women

“…In fact, there are two ways to explain the low prevalence of ultrasound autoimmune pattern in TPOAbpositive pregnant women: a low sensitivity of TUS or a low specificity of TPOAb-positivity. However, several previous studies have shown a good sensitivity of TUS for the diagnosis of early stages of Hashimoto's thyroiditis and subclinical hypothyroidism in non-pregnant subjects [14,15,16,18]. Similarly, the specificity of TPOAb in common population is high and was nearly 100 % for histological findings of Hashimoto's thyroiditis [19,20].…”

“…Twenty percent of unselected subjects had hypoechogenic and 13.7 % had irregular pattern in TUS [13]. Unselected subjects without overt thyroid diseases with autoimmune pattern in TUS had significantly higher TSH and increased risk of having of positive TPOAb in comparison with controls with normal TUS [14]. According to Dvorakova et al [15] decreased thyroid echogenicity can be an early indicator of serious thyropathies before laboratory dysfunction and clinical symptoms appear.…”

Clinical practice guidelines for the management of hypothyroidism

“…In a cross-sectional investigation of 4,649 randomly selected adult subjects, hypoechogenicity and irregular echo pattern at thyroid US were significantly associated with higher levels of serum TSH, even in subjects without overt thyroid disease, suggesting a possible use of thyroid US in detecting early and subclinical thyroid dysfunction (108). (A).…”

Aproximación al patrón de normalidad de TSH para la población chilena según Encuesta Nacional de Salud 2009-2010

“…Recientemente se ha planteado que también debiera excluirse de esta población a los que presenten alteraciones en el patrón ecográfico tiroideo, situación que haría más dificultosa la determinación de la normalidad poblacional [5][6][7] .…”