Introduction: Thyrotoxicosis is characterised by abnormally elevated circulating level of thyroid hormones. The most common aetiologies of thyrotoxicosis are Graves’ disease (GD) and destructive thyroiditis (DT). The correct diagnosis of thyrotoxicosis is crucial for appropriate management. Thyroid scan and thyrotropin receptor antibody (TSH-RAb) measurement are the modalities of choice for differentiating GD from DT. However, these modalities are limited by their high cost and availability. Colour flow Doppler ultrasound (CFDU) of the thyroid is inexpensive, safe, and readily available. This study was planned to evaluate the utility of CFDU and triiodothyronine (T3) to thyroxine (T4) ratio to differentiate GD from DT. Methods: Based on the clinical features, hormonal profile, thyroid scan, and TSH-RAb patients were diagnosed with DT and GD. All patients with DT and GD were subjected to CFDU. Results: A total of 158 patients of GD and 70 patients of DT were included in this study. The mean peak systolic velocity (PSV) of inferior thyroid artery (ITA), mean T3/T4 ratio, and thyroid volume were significantly higher in patients with GD in comparison to DT. Receiver operating characteristic analysis for PSV–ITA and T3/T4 ratio showed a cut-off of 38 cm/s (96.8% sensitivity and 98.6% specificity) and 19.2 (95.2% sensitivity and 92.9% specificity), respectively, to differentiate GD from DT. Conclusion: CFDU is a safe, non-invasive, inexpensive, and widely available modality. A combination of PSV–ITA and T3/T4 ratio can be useful in differential diagnosis of thyrotoxicosis and can be considered as an alternative to thyroid scan.
Nehara et al. (Sun,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: