[Thyroid Radiology Practice: Diagnosis and Interventional Treatment of Patients with Thyroid Nodules]

Abstract

Thyroid radiology practice is a medical practice in which thyroid diseases are diagnosed using imaging modality and treated by imaging-based interventional techniques, and the primary care target is thyroid nodular disease. Diagnosis of thyroid nodules is primarily done by ultrasound imaging and biopsy; thyroid nodules can be treated by non-surgical interventional treatment and thyroidectomy. Ethanol ablation is the first-line treatment for cystic benign nodules, and radiofrequency ablation is used for the treatment of benign solid nodules and recurrent thyroid cancers. Thyroid radiology practice has an essential clinical role in diagnosis and non-surgical treatment of thyroid nodular diseases, and treatment should be performed based on standard care guidelines for proper patient care. In order to provide the best care to patients with thyroid nodular disease, it is desirable to treat patients in the radiology outpatient clinic. Thyroid radiology practice centered on outpatient clinic practice needs to be expanded.

Fig. 1. K-TIRADS 2 (benign) and 3 (low suspicion). Diagnosis: benign follicular nodule.

A. K-TIRADS 2. Partially cystic (predominantly cystic) nodule with intracystic echogenic foci accompanying comet tail artifact (arrow). B. K-TIRADS 2. Spongiform nodule with multiple microcystic changes. C. K-TIRADS 3. Solid isoechoic nodule without any suspicious US features such as microcalcification, non-parallel orientation, and spiculated/microlobulated margin. D. K-TIRADS 3. Partially cystic (predominantly solid) and isoechoic nodule without any suspicious US feature. K-TIRADS = Korean Thyroid Imaging Reporting and Data System, US = ultrasound

Fig. 2. K-TIRADS 4 (intermediate suspicion) and 5 (high suspicion). Diagnosis: papillary carcinoma.

A. K-TIRADS 4. Solid hypoechoic nodule without suspicious ultrasound feature. B. K-TIRADS 4. Solid isoechoic (predominantly isoechoic) nodule with spiculated margin (arrows). C. K-TIRADS 4. Partially cystic (predominantly solid) isoechoic nodule with microcalcifications (arrow) and a punctate echogenic foci with comet tail artifact at the margin of the cystic component (long arrow). D. K-TIRADS 5. Solid hypoechoic nodule with spiculated margin (arrow), nonparallel orientation, and microcalcifications (long arrow). K-TIRADS = Korean Thyroid Imaging Reporting and Data System

Fig. 3. Ultrasound feature of gross extrathyroidal extension to the strap muscle (T3b).

The replacement of the strap muscles by the thyroid cancer is indicative of gross extrathyroidal extension to the strap muscles. Replacement of the strap muscles is defined as when thyroid cancer is protruding into the strap muscles and the tumor margin is indistinct and poorly differentiated from the strap muscles (arrowheads). Gross tumor invasion of strap muscles was found by surgery.

Fig. 4. Ultrasound feature of tumor invasion of the trachea (T4a).

Forming an obtuse angle with the trachea (arrow) is indicative of tumor invasion of the trachea. Tumor invasion of tracheal wall was found by surgery.

Fig. 5. Ultrasound feature of tumor invasion of the recurrent laryngeal nerve (T4a).

Tumor protrusion into the tracheoesophageal groove is indicative of tumor invasion of the recurrent laryngeal nerve (arrow). Tumor invasion of the recurrent laryngeal nerve was found by surgery.

Fig. 6. A 70-year-old woman with simple cyst in right thyroid gland treated by ethanol ablation.

A. Before ethanol ablation, a 10 mL simple cyst can be noted in the lower pole. B. During ethanol ablation, trans-isthmic approach using an 18G needle. C. One month after ethanol ablation, cyst decreased considerably without vascularity on Doppler ultrasonography. D. Twelve months after ethanol ablation, cyst decreased further and remained as a linear scar-like lesion without vascularity on Doppler ultrasonography.

Fig. 7. A 40-year-old woman with solid and cystic nodule in left thyroid gland treated by radiofrequency ablation.

A. Before radiofrequency ablation, a 3.5 cm sized well-defined solid and cystic nodule is noted in the left thyroid gland. B. Twelve months after radiofrequency ablation, the left thyroid nodule decreased in size (1.2 cm) and changed to hypoechoic calcified nodules.

Fig. 8. A 82-year-old woman with multiple recurrent thyroid tumors after total thyroidectomy at anterior neck involving strap muscles.

A, B. Before radiofrequency ablation, 3 recurrent tumors at ultrasonography and CT scan (white arrows). C. During radiofrequency ablation, the radiofrequency electrode is inserted into the mass and an echogenic area (arrow) inside the recurrent tumors is noted. Three recurrent tumors were treated in a single-session. D. One year after radiofrequency ablation, the three previously noted enhancing tumors disappeared completely on CT scan.