Ultrasound of Nodular Thyroid Enlargement

Thyroid ultrasound is an exquisitely sensitive technique for the detection of thyroid nodules and is able to image nodules as small as 2–3 mm. The prevalence of sonographically detected nodules that cannot be palpated is up to 50–60 % in individuals older than 60 [1]. Therefore, the challenge confronting the clinician is the identification of those nodules that have a higher probability of being a clinically relevant malignancy so that these can be targeted for fine-needle aspiration (FNA) biopsy and the recognition of those that may undergo sonographic surveillance. Furthermore, diffuse thyroid disorders, such as Graves’ disease and Hashimoto’s thyroiditis, image differently than the normal thyroid parenchyma, but it may be challenging to differentiate asymmetric involvement of the thyroid by one of these diffuse processes from a discrete thyroid nodule.