RESUMEN
OBJECTIVE: To assess the bedside utility of Spectral Doppler Ultrasound (SDUS) in the initial evaluation of patients presenting with thyrotoxicosis. METHODS: This is a retrospective cross-sectional study of patients diagnosed with thyrotoxicosis at an academic outpatient endocrinology clinic from August 2019 to November 2022. The thyroid arteries' peak systolic velocities (PSV) were measured bilaterally using SDUS. PSV ≥40 cm/s in at least a single thyroid artery was considered a reasonable cut-off for Graves' disease and PSV of perinodular artery ≥ 25 cm/s for toxic adenoma. RESULTS: We identified 73 patients. Mean age ± standard deviation 45.2 ± 16.4 years, 54 (74.0%) were female, 49 (67.1%) were Caucasian, 23 (31.5%) were African American, and 1 (1.4%) was Asian. The confirmed diagnoses were 48 (65.8%) Graves' disease, 13 (17.8%) thyroiditis, four (5.5%) toxic adenoma, four (5.5%) amiodarone-induced thyroiditis type 2, 1 (1.4%) toxic multinodular goiter, 1 (1.4%) had an unremarkable repeat thyroid function testing, and two (2.7%) were unconfirmed. Diagnosis based on the SDUS initial assessment was accurate in 65 (89.0%) of the patients, and it was conclusive and confirmatory during the initial encounter in 55 (75.3%) of the patients before additional testing. A thyroid scan was obtained in nine (12.3%) patients. Incorrectly diagnosed patients were observed in two patients of each of the following categories: Graves' disease, thyroiditis, toxic adenoma, and unconfirmed diagnoses. CONCLUSIONS: SDUS can be a valuable, efficient, and cost-effective bedside tool in the initial assessment of patients presenting with thyrotoxicosis.