Role of dynamic MRI in differentiating benign from malignant follicular thyroid nodule

Objectives Thyroid nodular swellings are very common, consisting of both benign and malignant ones. Fine needle aspiration cytology is an excellent diagnostic modality for papillary cancers, medullary cancers, colloid goiter and lymphoma but fails in differentiating follicular adenomas from carcinomas. The purpose of this study was to evaluate role of Dynamic MRI with signal intensity time curve evaluation in differentiating benign from malignant follicular nodules. Materials and methods This study was carried out in Department of Surgery in collaboration with department of Radiodiagnosis, Maulana Azad Medical College, Delhi. 28 patients with solitary thyroid nodule (STN) having follicular etiologies were included in the study. Dynamic MRI with signal intensity time curve analysis was carried out in all the cases and findings were compared with the final diagnosis based on histopathological examination of surgical specimen. Results In the present study, rapid enhancement was seen in 87.5% of malignant cases and washout pattern was seen in 87.5% of malignant STN (p = 0.019). Only 20% of the benign lesions showed washout pattern (p = 0.0034). Benign cases demonstrated gradual enhancement in 85% cases as compared to 12.5% in malignant STN (p = 0.0098). Conclusion This study suggests that signal intensity time curve may help in differentiating benign from malignant follicular thyroid nodules.