ROLE OF COLOUR DOPPLER ULTRASONOGRAPHY IN DIFFERENTIATING BENIGN AND MALIGNANT THYROID NODULES

Abstract

Objective: To determine the validity of Colour Doppler Ultrasonography in differentiating benign from malignant thyroid nodules in patients attending outpatient department of Radiology of Combined Military Hospital, Rawalpindi, keeping fine needle aspiration as reference.
Study design: Validation study.
Place and duration: The Department of Radiology, Combined Military Hospital (CMH), Rawalpindi from June to December 2009.
Patients and Methods: All patients with thyroid nodules were included for diagnostic workup. Colour Doppler study was carried out recording the size and consistency of the thyroid nodule with special emphasis to vascularity pattern. US findings were noted. Ultrasound was followed by fine needle aspiration from Armed Forces institute of Pathology (AFIP), Rawalpindi. Findings on CDUS were analyzed in light of AFIP report.
Result: Among the 107 thyroid nodules studied, 6 nodules were proven to be malignant on FNA. Of these 6 malignant nodules, only 3 were picked up by Colour Doppler ultrasound. Four were wrongly labeled as malignant by the vascularity pattern shown on Colour Doppler Ultrasound. Colour Doppler ultrasound showed a sensitivity of 50%, specificity of 96%, NPV of 97%, and PPV of 42.9%.
Conclusion: The Colour Doppler characteristics of a thyroid nodule cannot be used to predict or exclude malignancy confidently. Although the future of duplex Ultrasonography is changing, FNAB is still needed to determine the nature of the nodule.