Relationship between the sonographic appearance of the thyroid and the clinical course and autoimmune activity of Graves' disease

Purpose. The aim of this study was to investigate the relationship between thyroid echogenicity and clinical course/immunologic parameters in Graves' disease. Methods. Two hundred and six outpatients with Graves' disease (31 men, 175 women; 46 ± 23 years old) were studied with thyroid sonography and color Doppler sonography. Forty-five patients were treated for active hyperthyroidism, 161 were euthyroid (85 immediately before withdrawal of antithyroid drug at maintenance doses, 76 in stable remission after withdrawal of antithyroid treatment). Free triiodothyronine, free thyroxine, thyrotropin, and disease-specific autoantibodies (antithyrotropin-releasing hormone antibody) were determined in all patients. Results. The ultrasound images were classified on the basis of homogeneous, finely unhomogeneous, or micronodular appearance. The proportion of unhomogeneous plus micronodular patterns was greater in hyperthyroid (77.8%) than in euthyroid patients (62.1%). In the latter group, the pattern distribution was significantly different in patients who were antibody positive relative to patients who were antibody negative (p <0.01). In the stable remission subgroup, the pattern distribution differed according to thyrotropin levels (p <.01). There was a correlation between echopattern and color Doppler sonography as vascularization variables progressively increased in the transition from homogeneous to unhomogeneous and micronodular echopattern (most evident echotexture changes). Conclusions. A sonographic-based classification in Graves' disease can distinguish subgroups of patients with different clinical courses and disease activity. This procedure is easy to perform and correlates well with clinical findings.