Endocrine Abstracts

Objective: To evaluate the role of thyroid blod flow assessment by color-flow Doppler ultrasonography in the differential diagnosis of thyrotoxicosis in an outpatient endocrinology clinic.

Material and methods: Consecutive patients with thyrotoxicosis presenting to our center between January–December 2013 were included in the study. Clinical date were collected and measurements of TSH, serum free thyroxine and TSH receptor antibodies were performed. Thyroid glands were evaluated by the same endocrinologist expert in thyroid ultrasound, whith color-flow Doppler ultrasonography (Logic Scan 64, B-Side Medical System) whit a 10-MHz linear transducer. Were assessed size, vascularity and peak systolic velocity of the inferior thyroid artery (PSV-ITA). Gland vascularity was categorized into 4 grades. PSV-ITA >40 cm/s is considered significantly increased, suggestive of Graves’ Disease (GD). ^99mTc pertechnetate scan was done in patients when the diagnostic was not clear. U-Mann–Whitney test and Fisher exact test were used for statistical analysis.

Results: A total of 45 patients with thyrotoxicosis were enrolled in this study. The suspected diagnostic in the first consultation was: 2 toxic adenomas, 4 toxic multinodular goiters, 24 GD, 15 destructive thyrotoxicosis (DT) (3 type II amiodarone thyroiditis, 3 subacute thyroiditis, 2 Hashitoxicosis, 3 silent thyroiditis) and 4 normal ultrasound. Toxic multinodular goiters and toxic adenomas were confirmed by ^99mTc scan. Intraparenchymal vascularity of thyroid gland was greater in patients with GD than in patients with DT (type 3/4: 100% vs 9% respectively; P<0.001). Thyroid blood flow assessed by PSV-ITA was significantly higher in patients with GD than in patients with DT (62.3±13.7 cm/s vs 27.4±9.2 cm/s; P>0.001).

Conclusions: The usefulness of color-flow doppler ultrasonography of the thryroid gland goes beyond the assessment of thyroid nodule. In patients with thyrotoxicosis provide valuable information about underlying thyroid functional status and is useful in the differential diagnosis.