Graves’ disease (GD) is an autoimmune,
chronic pathology of the thyroid gland,
first 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,
drugs and infections).
The disease is characterized by one or more changes: hyperthyroidism,
skin changes and pretibial myxedema,
around 5% less common,
and other symptoms 90 to 95%.
the T lymphocytes become sensitive to antigens presented in thyroid gland,
and stimulate B lymphocytes to synthesize antibodies against antigens.
One of these antibodies,
the TSH-R Ab is aimed against the TSHmembrane receptor of thyroid cells and it is able to stimulate cells function.
Circulating antibody is associated with disease positivity and recurrence.
This pathology incidence is higher in women (around 5 - 10:1)  ,
clearly in any age,
although 20 – 40 years old more often.
It is common in Caucasians and Asians,
compared to blacks .
excess iodine intake in certain regions,
viral or bacterial infection,
lithium treatment (alters immune system),
are some factors that can stimulate immune response in GD.
Treatment options for hyperthyroidism caused by GD are: antithyroid drugs (tapazole,
metimazol and propylhtiouracil),
radioiodine (131I) and,
the last resort,
surgery  .
The three treatments are effective,
present problems and/or side effects,
and none offers,
an absolute cure for the disease.
One of the most relevant clinical practice,
aspects in GD patients management is to distinguish GD in initial phase,
from other types of destructive thyrotoxicosis,
in addition to evaluate therapeutic methods and eficiente follow up,
as well as predict early recurrence or remission of disease.
Scintigraphy with pertechnetate (99mTc) and TSH levels dosage are considered the choice for this purpose.
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,
non-invasive and radiation free method,
providing initial diagnosis and patients with GD follow up.
this method is used in differential diagnosis with other causes of thyrotoxicosis in the early stage -.
The aim of this study is to compare the ultrasonographic findings,
Bmode and colorDoppler,
in patients with Graves disease before and after radioiodine (131I) therapy (1,
3 and 6 months).
To demonstrate the changes in the thyroid volume and parenchyma vascularization and in the systolic peak velocity of the inferior thyroid arteries after treatment.