Diagnostic value of dynamic contrast medium enhanced magnetic resonance imaging in preoperative detection of thyroid carcinoma.

OBJECTIVE To assess the diagnostic value of dynamic contrast medium-enhanced magnetic resonance imaging (DCE-MRI) in detection of thyroid carcinoma compared with fine-needle aspiration biopsy and frozen section analysis in multinodular goiter. DESIGN Prospective clinical study. SETTING University hospital. PATIENTS Thirty consecutive patients with nodular goiter without any clinical risk and symptoms associated with thyroid carcinoma were studied. Twenty-five patients had euthyroid multinodular goiter, and 5 had toxic nodular goiter. Scintigraphy, ultrasonography, and DCE-MRI were performed preoperatively in all patients, as well as fine-needle aspiration biopsy and frozen section analysis in 17 patients with dominant cold nodules. MAIN OUTCOME MEASURES Contrast enhancement patterns on DCE-MRIs and histopathologic results of thyroidectomy specimens were correlated. The sensitivity, specificity, diagnostic accuracy, and positive and negative predictive values of DCE-MRI and the results of fine-needle aspiration biopsy and preoperative frozen section analysis to detect thyroid carcinoma were compared. RESULTS Thyroid carcinoma was found in 11 patients (36.7%), but was clinically significant in only 4 (13.3%). Delayed washout pattern of contrast enhancement significantly correlated with a histologic diagnosis of thyroid carcinoma (P < .001). The conditional probability of thyroid cancer in a patient with multinodular goiter with a delayed washout pattern was 0.78. The sensitivity and diagnostic accuracy of DCE-MRI to detect thyroid carcinoma was higher compared with fine-needle aspiration biopsy and frozen section analysis (100% vs 50% and 85.7%, and 90% vs 70.6% and 87.5%, respectively). The negative predictive value of DCE- MRI was 100%, ruling out thyroid carcinoma in all patients with benign goiter. CONCLUSION Dynamic contrast-enhanced magnetic resonance imaging is useful to detect or exclude thyroid carcinoma with high diagnostic accuracy in patients with multinodular goiter when results of other diagnostic methods are inconclusive.