Diagnostic Performance of Gray-scale versus Combined Gray-scale with Colour Doppler Ultrasonography in the Diagnosis of Malignancy in Thyroid Nodules

Objective: To compare diagnostic performance of gray-scale ultrasound and combined gray-scale ultrasoundwith color Doppler ultrasound in predicting malignancy of thyroid nodules by using tissue diagnosis as thereference standard. Design: Diagnostic test with prospective data collection. Materials and
Methods: BetweenNovember 2007 and October 2008, 31 patients (16 with solitary thyroid nodules and 15 with multiple thyroidnodules) were preoperatively evaluated with gray-scale ultrasound and color Doppler ultrasound. The noduleswere classified as benign or malignant according to the established ultrasound criteria and were later comparedwith histologic findings obtained from surgical specimens. The sensitivity, specificity, positive predictive value(PPV) and negative predictive value (NPV) of gray-scale US and combined gray-scale with color Doppler USwere evaluated using histology as the reference.
Results: The sensitivity, specificity, PPV and NPV of gray-scaleultrasonography were 80.0%, 84.6%, 50.0% and 95.7%, respectively. The sensitivity, specificity, PPV and NPVof preoperative combined gray-scale US with color Doppler ultrasonography were 40.0%, 96.2%, 66.7% and89.3%, respectively.
Conclusion: Combination of gray-scale US with color Doppler US findings improvesspecificity and PPV in the diagnosis of malignancy in thyroid nodules.