Purpose: To evaluate the necessity of MRI and scintigraphy in addition to US in patients with thyroid diseases.
Patients and Methods: In 2003-07 2794 patients with various thyroid diseases were surveyed. US was performed in all patients, scintigraphy – 224 (8.0%), MRI – 65 (2.3%). In case of thyroid carcinoma the diagnosis was verified before operation by fine needle aspiration biopsy with US guidance.
Results: The US/USD, tissue harmonic imaging, 3D-reconstruction allowed defining thyroid volume changes, focal masses and specifying their number, location, structure, vascularity, spatial relations with other neck organs. Sensitivity of US in thyroid carcinoma was 94.2%, specificity – 77.8%, diagnostic accuracy – 92.7%. In substernal thyroid, doubtful US data, for thyroid residue condition assessment in recurrent goiter, for evaluation of thyroid carcinoma invasion and mediastinal lymph nodes metastases MRI was applied. MRI sensitivity in thyroid carcinoma was 76.5%, specificity – 50.0%, diagnostic accuracy – 66.7%. Thyroid scintigraphy was performed for definition of nodular functional autonomy in hyperthyroidism, in substernal and atypical thyroid location. “Cold nodules” corresponded to carcinoma in 20.8%, “hot nodules” in 10.4% of cases.
Conclusions: US is the basic visualization modality for thyroid diseases and is sufficient in 95.4% patients. In case of doubtful US data, substernal goiter, for thyroid residue condition assessment in recurrent goiter, evaluation of thyroid carcinoma invasion and mediastinal lymph nodes metastases MRT is indicated. For functional autonomy assessment scintigraphy is indicated.