Accuracy of American College of Radiology Thyroid Imaging Reporting and Data System in characterisation of thyroid nodules: A tertiary hospital study in India

Abstract

Background: Thyroid nodules (TNs) are commonly and frequently encountered in the day‑to‑day clinical practice. Clinical suspicion of malignancy as well as patient anxiety is the frequent reasons for fine‑needle aspiration cytology or biopsy (FNAC/B) of TN. American College of Radiology has developed a Thyroid Imaging Reporting and Data System (ACR TI‑RADS) based on TN ultrasound features to suggest malignancy to minimise the number of TN subjected to FNAC/B. Aim to assess the diagnostic accuracy of ACR TI‑RADS in our Tertiary Hospital Health Facility. Patients, Materials and Methods: Sixty‑nine patients with TN included in our study following institutional ethics committee approval and written informed consent underwent high‑resolution ultrasonography followed by FNAC using a high‑frequency linear transducer on Siemen Acuson S3000 ultrasound scanner. The data were recorded in the predesigned proforma followed by statistical analysis to assess the diagnostic accuracy of ACR TI‑RADS. Results: Our study had female predominance (50/69) with the left side more commonly affected (37/69). The mean age of the participants was 42.2 ± 15.6 years with significantly higher age at presentation in those with malignant TN. Mixed nodules were predominant (46/69) with nearly half of the malignant nodules being solid and only 8/61 benign nodules being solid. Although the majority of the nodules were hyperechoic (50/69 including 2 malignant), a significant number of the hypoechoic/ very hypoechoic nodules (6/14) were malignant with only 8/61 benign nodules being hypoechoic. Half of the malignant nodules (4/8) had lobulated or ill‑defined margins, whereas only 2/61 benign nodules had similar margins. The majority (5/8) of the malignant TN had internal punctate echogenic foci with only 1/61 benign TN showing similar appearance. Half of the malignant TN (4/8) had lymphadenopathy, whereas it was noted in only 2/61 cases of benign TN. Conclusions: TNs though have a high prevalence, but malignant TNs are uncommon with majority being solid, taller than wider, hypoechoic with microcalcifications. The presence of adenopathy is usually a feature of malignant thyroid nodule rarely seen with benign nodules. Thus, to summarise all TNs should be thoroughly evaluated as per ACR TI‑RADS for stratification of risk of malignancy.