Graves' Disease Thyroid Color-Flow Doppler Ultrasonography Assessment: Review Article

Abstract

Graves' disease, as known today, is an autoimmune, diffuse, chronic disease of thyroid gland, as described by Robert Graves in 1835. It presents genetic predisposition and unknown etiology evidence, which is influenced in its development by several factors, including environment (dietary iodine intake, stress, drugs and infections). The disease is characterized by one or more changes: hyperthyroidism, goiter, ophthalmopathy, skin changes and pretibial myxedema, around 5% less common, and other symptoms 90% to 95%. One of the most relevant clinical practice aspects in Graves' disease patients management is to distinguish Graves' disease in initial phase, from other types of destructive thyrotoxicosis, in addition to evaluate therapeutic methods and efficient follow up, as well as predict early recurrence or remission of disease. Scintigraphy with pertechnetate (99 mTc) and TSH levels dosage are considered the choice for this purpose. However, they present some technical difficulties, as they are not widely available and have contraindications. In this scenario, thyroid color-flow doppler ultrasonography (US Doppler) presents a viable alternative, as a widely available, low cost, non-invasive and radiation free method, providing initial diagnosis and patients with Graves' disease follow up. In adittion, this method is used in differential diagnosis with other causes of thyrotoxicosis in the early stage.

Can Color Doppler Ultrasonography Differentiate Thyrotoxicoisis in Graves Disease from Subacute Thyroiditis?

“…It was clearly observed that cent percent of Graves' disease patient had increased thyroid blood flow in comparison to subacute thyroiditis in which more than three quarters showed decreased flow. Cut off value of 30cm/sec was considered in differentiation between Graves' disease from thyroiditis based on a review of relevant literature [3,4]. Our findings were in agreement with the findings of those investigators revealing more than 90% of the Graves' patient above the mentioned cut off while 80% of subacute cases were below.…”

“…Thyroid blood flow was seen by color Doppler power mode. PSV of the inferior thyroid artery of >30cm/sec was considered significantly high and suggestive of Graves disease and <30cm/sec for thyroiditis [3]. RAIU was considered as the gold standard.…”

“…Its evaluation can be both qualitative (visual assessment of thyroid vascularity) and quantitative [measuring peak systolic velocity (PSV), end diastolic and mean velocities in the inferior thyroid arteries]. Normal PSV in intrathyroidal arteries ranges between 15 to 30cm/sec but it can rise to over 100cm/sec in certain pathologic conditions like Graves' disease [3]. CFD reveals a spectacular thyroid inferno with marked hypervascularity both in systole and diastole.…”

Role of Color Doppler Ultrasonography in Differentiation of Graves’ Disease from Thyroiditis: A Prospective Study

“…Thus, surgeons performing USG examination will be an extension of clinical evaluation in the outpatient department with the results available immediately for choosing the management strategy. 7,8 Ralls et al 9 in 1987 used CD in Graves' patients to show the increased blood flow in the thyroid gland. They coined the term thyroid inferno, indicating diffuse increase in thyroid parenchyma vascularization.…”

Quantitative analysis of thyroid gland blood supply in children and adolescents

“…However, to date, those features have been general findings for these diseases and are not helpful in the differential diagnosis. Detection of increased thyroid vascularity on the Doppler US examination is very significant for thyroid diseases (5). Thyroid parenchymal blood supply has been shown to increase, especially in Graves' disease and early stages of Hashimoto's thyroiditis.…”