[The color-coded duplex sonography and contrast-enhanced magnetic resonance tomography of scintigraphically cold thyroid nodules].

In order to establish diagnostic criteria, colour-coded duplex sonography was performed on 40 patients who had a total of 43 operatively confirmed thyroid lesions which were scintigraphically "cold" (28 adenomas, 8 carcinomas, 4 cases of thyroiditis and 3 cysts). 32 of these patients also had MRT with T2- and T1-weighted images before and after injection of Gd-DTPA (0.1 mmol/kg). Adenomatous nodules and adenomas showed a peripheral vascular halo on colour-coded duplex sonography with a sensitivity of 96% and a specificity of 93%. Malignant lesions showed marked central vascularisation and on B-images irregular marginal structures. Adenomas and adenomatous nodules showed hyperintense areas on T1-weighted unenhanced MR images and/or homogeneous uptake in the lesion (sensitivity 100%, specificity 77%). Malignant lesions typically showed an irregular margin with increased contrast uptake on MRT. If sonography and colour-coded duplex sonography is unable to classify a lesion with any degree of assurance then MRT with Gd-DTPA enhancement should be performed.