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 ultrasound with color Doppler ultrasound in predicting malignancy of thyroid nodules by using tissue diagnosis as the reference standard.

DESIGN

Diagnostic test with prospective data collection.

MATERIALS AND METHODS

Between November 2007 and October 2008, 31 patients (16 with solitary thyroid nodules and 15 with multiple thyroid nodules) were preoperatively evaluated with gray-scale ultrasound and color Doppler ultrasound. The nodules were classified as benign or malignant according to the established ultrasound criteria and were later compared with 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 US were evaluated using histology as the reference.

RESULTS

The sensitivity, specificity, PPV and NPV of gray-scale ultrasonography were 80.0%, 84.6%, 50.0% and 95.7%, respectively. The sensitivity, specificity, PPV and NPV of preoperative combined gray-scale US with color Doppler ultrasonography were 40.0%, 96.2%, 66.7% and 89.3%, respectively.

CONCLUSION

Combination of gray-scale US with color Doppler US findings improves specificity and PPV in the diagnosis of malignancy in thyroid nodules.