Computed tomography demonstrating left suppurative thyroiditis due to left pyriform sinus fistula

CT of the neck in a 2-year-old patient presenting with swelling and tenderness of the left neck.
(A) A CT scan of the neck at the level of the thyroid gland shows an irregular, peripherally enhancing low attenuation left perithyroidal collection (arrow) in a patient with suppurative thyroiditis due to a left pyriform sinus fistula.
(B) A coronal reconstruction of the CT scan shows the superomedial collection displacing the poorly defined superior pole of the left lobe of the thyroid gland (arrow).