Jerry George, Mattavana Ramakrishna Pillai Balachandran Nair, Kiran Thilakarajan
BACKGROUND Differentiation between thyroiditis induced thyrotoxicosis and Graves' disease is needed for selection of proper therapy. It is often difficult to differentiate between them without performing thyroid scintigraphy. Colour Flow Doppler Sonography (CFDS) is gaining importance for the functional evaluation of the thyroid diseases. The purpose of the study was to determine the value of CFDS for differentiating between thyroiditis induced thyrotoxicosis and Graves’ disease. MATERIALS AND METHODS Fifty patients with clinical and lab signs of hyperthyroidism were evaluated. Clinical history was taken, and physical examination and thyroid function tests were performed for all patients. Conventional grey scale sonography was done, followed by CFDS. Peak systolic velocity (PSV) measurements were obtained from both inferior thyroid arteries. Results were compared with Technetium 99 scanning which was used as a golden standard. The patients were divided into two groups: 32 cases with Graves’ disease and 18 cases with thyroiditis based on thyroid scintigraphy. The patients had suppressed TSH levels and clinical symptoms also supported the diagnosis. RESULTS The Peak systolic velocity of right inferior thyroid artery was found to be elevated in patients with Graves’ disease than in patients with thyroiditis (P <0.001 in right inferior thyroid artery). It had a sensitivity of 90.6% and a specificity of 88.9% in differentiating the causes of thyrotoxicosis. CONCLUSION Peak systolic velocity is an inexpensive, fast, and noninvasive imaging procedure. Hence it will be very useful in the differential diagnosis of thyrotoxicosis, especially when thyroid scintigraphy by radioactive materials is contraindicated in special situations like pregnancy and in places where nuclear imaging is not easily accessible.
