A Study of Efficacy of High-Resolution Sonography in Differentiating Benign and Malignant Nodules of Thyroid

Background: Thyroid nodules are common. Their clinical significance lies in the need to rule out malignancy, which accounts for 4.0% to 6.5% of all nodules, assess their functional status, and determine the presence of any pressure symptoms. The use of advanced and highly sensitive imaging techniques has led to an increased detection rate of incidental thyroid nodules in recent years. This study evaluated the efficacy of high-resolution sonography in cases of thyroid nodules presenting to our hospital. Methods: Thyroid nodules were examined on SIEMENS ACUSON 300 machine via a 5-10 MHZ linear probe. Sonographic findings of each thyroid nodule were assessed just before the FNA examination. USG and pathological findings were blinded to each other. Nodules were evaluated for their size, shape, margins, echogenicity, presence of calcification, presence of peri lesional halo, and internal composition. The margins were smooth or irregular, the shape was lobulated or round and echogenicity was iso, hypo, or hyperechoic regarding thyroid. Results: This study of 135 thyroid nodules in 100 patients (91 female, 9 male) evaluated ultrasound (USG) features for malignancy prediction. Histopathology confirmed 18.5% as malignant. Smooth margins (98% specificity) and predominantly cystic content (98.5% NPV) strongly suggested benignity. Poorly defined margins, calcifications, absent/thick halo, and marked hypoechogenicity were more frequent in malignant nodules, though with varying sensitivity and PPV. Combining USG features, as in TIRADS, proved crucial for accurate risk stratification, with high NPVs aiding in ruling out malignancy. Conclusion: Grayscale USG findings proved valuable in identifying clinically significant thyroid nodules and distinguishing between malignant and benign ones. Our study highlighted that malignant nodules commonly exhibited features such as poorly defined margins, microcalcifications, marked hypoechogenicity, and cystic predominance, all of which demonstrated high diagnostic accuracy.