Role of ultrasonography (USG) and color Doppler in the evaluation of thyroid nodules and its association with USG-guided FNAC - A cross-sectional study.

Abstract

Thyroid diseases affect approximately 42 million people in India. The majority (15%-40%) of these cases remain asymptomatic and benign and warrant special investigations such as ultrasonography (USG) and fine-needle aspiration cytology (FNAC) for diagnosis. Early diagnosis and management of thyroid disorders determine the disease course in many patients. To determine the role of USG and color Doppler in the evaluation of thyroid nodules and its association with USG-guided FNAC. We did a cross-sectional analytical study over 2 years, where we recruited 108 patients with thyroid swelling attending the OPD. We used a semi-structured data collection proforma that captured information on sociodemographic details, clinical symptoms, physical examination, and all ne cessary laboratory investigations. All patients underwent USG, color Doppler, and FNAC as a part of the investigation of thyroid nodules. The diagnostic value of ultrasound and Doppler parameters was assessed in terms of sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for detection of malignancy in comparison to FNAC. Approximately 155 nodules were identified from the selected 108 cases, and the prevalence of malignancy among the selected thyroid nodule patients was found to be 9.1%. We observed that malignant tumors were likely to be solitary with lobulated margins, >2 cm in size with <50% peripheral halo, with markedly hypoechoic, predominantly solid, with nodal involvement and extrathyroidal extension, microcalcifications, and central vascularity. We also observed that tumors that had USG characteristics of being taller than wide (91%), poorly defined margins (92%), marked hypoechoic (95%), and microcalcifications (96%) had the highest diagnostic accuracy in detecting malignancy when compared to FNAC. Thus, through our study findings, we conclude that USG and color Doppler can serve as vital tools for the evaluation of thyroid nodules with high sensitivity and specificity.