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Imaging

Ultrasound of the thyroid may be used to reveal whether structures are solid or filled with fluid, helping to differentiate between nodules and goitres and cysts. It may also help differentiate between malignant and benign lesions.

When further imaging is required, a radiolabelled iodine-123 or technetium-99 uptake scan may take place. This can determine the size and shape of lesions, reveal whether nodules or goitres are metabolically active, and reveal and monitor sites of thyroid disease or cancer deposits outside the thyroid.

A fine needle aspiration of a sample of thyroid tissue may be taken in order to evaluate a lesion seen on ultrasound which is then sent for histopathology and cytology.

Computed tomography of the thyroid plays an important role in the evaluation of thyroid cancer. CT scans often incidentally find thyroid abnormalities, and thereby practically becomes the first investigation modality.