All cases of the study will be diagnosed as Graves' by History, examination, laboratory (FT3, FT4, TSH & TRAbs), X-ray on left wrist for bone age, neck grey scale ultrasonography for thyroid gland size, shape, echotexture, vascularity and nodule characters if present with TIRAD score calculation.

Then Color flow doppler ultrasound will be done to asses thyroid volume, number of vessels per square cm and inferior thyroid artery peak systolic velocity, end diastolic velocity and resistive index. Patients then will receive carbimazole antithyroid drug at dose 0.25-0.5 mg/kg/day PO & the dose will be titrated according to thyroid function test after 4-6 weeks.

Beta-adrenergic blockade will be added to all symptomatic cases. Regular follow up will be done every month of first 3 months of diagnosis and then every 3 months for 2 years by clinical and thyroid function test to asses response, compliance, complications, drug side effects, remission and relapses.

Doppler ultrasound will be done at 0, 12 and 24 months.

Inclusion Criteria:

• All newly diagnosed children with clinical and laboratory hyperthyroidism (high T4 & low TSH) with positive TRAbs.

Exclusion Criteria:

• Patients receiving radioiodine Patients underwent thyroid surgery History of neck radiation or neck surgery

children who will come at pediatric endocrinology outpatient clinic of Assiut University Children's Hospital meeting our inclusion criteria.