Endocrine Abstracts

Introduction: Nowadays, ultrasonography (USG) is being used very commonly and indispensably for diagnosing thyroid diseases. Heterogeneous appearance of thyroid parenchyma is associated with positivity for thyroid autoantibody and hypofunctioning of thyroid gland. On the other hand, it is not determined whether thyroid parenchyma appearing totally of normal ecogenity on USG is related to presence normal thyroid function tests or otherwise. The objective of our study was evaluate the relationship between normal thyroid USG appearance and thyroid function tests with thyroid autoantibodies.

Material and methods: The study was planned prospectively and 218 patients’ thyroid USG images and laboratory tests were evaluated. The participants were classified into two groups composed of the homogeneous/ normoecogenic and the heterogeneous group, according to thyroid parenchyma appearance on USG.

Findings: We acquired homogeneous images on 103 cases and heterogeneous images on 115 of the cases. TSH level, anti-Tg and anti-TPO titres and thyroid volume was found to be significantly higher in heterogeneous parenchyma group (P<0.001). 83 cases with normal USG images (80.5%) had normal TSH levels and 7 cases in this group had positive anti-Tg (8.4%) and 23 cases had positive anti-TPO (27.7%). Out of the heterogeneous parenchyma group composed of 115 cases; 46 patients (40%) had high TSH level and 9 of them (19.6%) had positive anti-Tg and 35 (76.1%) had positive anti-TPO. We observed no difference in between the groups in regards to fT₃ and fT₄ levels. Age and thyroid volume were determined to correlate significantly and positively (r=0.171, P=0.012).

Conclusions: The thyroid gland ‘normal’ appearing on USG imaging, possibly accompanies normal serum thyroid function tests and negativity for thyroid antibodies. According to our results, thyroid USG is a perfect device for predicting normal thyroid functions, which could probably avoid unnecessary future laboratory tests as well.