Role of Color Doppler Ultrasonography in Predicting Risk of Malignancy in Thyroid Nodules in Correlation with Ultrasound Guided Fine Needle Aspiration Biopsy

Introduction: Thyroid nodules are commonly encountered on ultrasonographic studies. Color doppler ultrasonography can be utilized to help in differentiating malignant and nonmalignant nodules based on different imaging criteria. Objective: The objective of this study is to correlate sonographic and color Doppler characteristics of thyroid nodules with the results of sonographically guided fine-needle aspiration biopsy to establish the relative importance of these features in predicting risk for malignancy. Patients and Methods: In this study, 103 patients (81 women and 22 men with mean age of 45.2 years) were included between April 2012 and June 2013. The cases were subjected to complete U/S and Doppler examination and the results were compared to U/S guided FNAC. Certain U/S and Doppler criteria were analyzed to predict risk of malignancy including; number, size, echogenicity, structure, margin, calcifications, vascular pattern and RI of the nodules. Results: The most significant U/S and Doppler criteria that predict malignancy in thyroid nodules are; irregular borders (sensitivity=66.6% and specificity=76.4%), numerous micro calcifications (sensitivity=16.6% and specificity=100%), exclusively central vascularity (sensitivity=50% and specificity=100%) and more central vascularity (central more than peripheral) sensitivity=88.9% and specificity=87%. Conclusion: The presence of more central vascularity in thyroid nodules strongly suggests malignancy and these nodules should undergo FNAC and that absence of central vascularity in thyroid nodules strongly suggests benignity. Thus, we recommend adding Doppler examination in the evaluation of the thyroid nodules to increase the specificity of U/S examination and to guide the FNAC biopsy.