Neck Ultrasound After Thyroid Surgery

Abstract

The volume of neck surgery in thyroid diseases ranges from the resection of a lobe fragment to total thyroidectomy with radical neck dissection. The ultrasound image of the thyroid bed depends largely on the volume of the thyroid tissue removed, the technique of surgery, and on the time after the operation. The immediate postsurgical period is characterized by the infiltration of the thyroid bed and subcutaneous fat, with possible visualization of hematomas and suture material. Granulomas, calcifications, and fluid structures may appear later. This may lead to ultrasound hyperdiagnosis of disease recurrence. The ultrasound image of the thyroid bed 3 months after organ-preserving operations (subtotal resection, hemithyroidectomy) depicts the thyroid residue with regular margins, homogeneous structure, and unchanged or slightly decreased/increased echodensity. Fibrotic changes are often seen in the bed of the removed lobe with vascular bundles displaced medially. The remnants of organized hematomas may be detected in rare cases as dense heterogeneous inclusions with indistinct contours, calcifications, suture granulomas, or individual cysts. Several operations for thyroid cancer and malignant tumors of the head and neck require the removal of different neck structures. In some cases, cervical and supraclavicular lymph nodes, the submandibular salivary gland, sternomastoid and omohyoid muscles, and the internal jugular vein are excised, resulting in corresponding sonographic changes.