Differentiation of thyroid nodules using diffusion-weighted MRI

Background: Thyroid nodule evaluation is usually done using a fine needle aspiration cytology/biopsy. The aim of this study was to evaluate the role of diffusion weighted imaging to differentiate benign from malignant thyroid nodules. Methods: Sixty-one patients, 15 males and 46 females (30–70 years, mean age 49.08 years) with thyroid nodules were included in the study. Routine MRI of neck and diffusion-weighted MR imaging was performed using multiple b-values. Apparent diffusion coefficient (ADC) values were done for the different b-values. Histopathological results of the thyroidectomy samples were obtained. Comparison of apparent diffusion coefficient values of thyroid nodules with the histopathology was done. Results: The pathology results showed that there were 38 and 23 benign and malignant thyroid nodules respectively. ADC value for b-values of 0–300 s/mm^2 was used to evaluate the ADC values for benign and malignant thyroid nodules which were significant (p 0.001). Higher ADC values were seen in benign nodules (ADC: 2.32 ± 0.44 · 10–3 mm^2/s) than malignant ones (1.40 ±0.40 · 10–3 mm^2/s). Conclusion: Differentiation of thyroid nodules whether benign or malignant can be done using the diffusion-weighted MR technique.