Role of Grey Scale and Doppler Sonography in Thyroid Nodules and Correlation with Fine Needle Aspiration Cytology

Thyroid Nodules and Correlation with Fine Needle Aspiration Cytology

Abstract

Introduction: Discrete lesions that are radiologically distinct from surrounding thyroid parenchyma are defined at thyroid nodules. They may be clinically palpable or may be detected incidentally on high resolution ultrasonography. Though the prevalence of thyroid nodules in the general population is quite high but majority of them are benign. High resolution ultrasonography plays an important role in defining the characteristics & number of lesions but fine needle aspiration cytology is gold standard for final diagnosis allowing true distinction between benign and malignant nodules. Material and Methods: This hospital based, observational study was performed in the department of Radiodiagnosis of our institution on fifty patients presenting with thyroid swelling or palpable nodule with or without symptoms after obtaining a written consent. Each patient underwent high resolution ultrasonography by 7-12MHz linear transducer followed by FNAC using 23G needle. The results were statistically analyzed using appropriate tools and methods. Results: Majority of the patients in our study were female with maximum in the 30-60yrs age-group. FNAC failed to give the final diagnosis in 4/50 patients due to inadequacy of sample. The diagnosis of benign & malignant was quite accurate with USG. Majority of the adenoma were hyperechoic on USG, while majority of malignant nodules were hypoechoic on USG. Characteristic features of malignancy were hypoechogenicity, presence of microcalcification, invasion of strap muscles, presence of cervical adenopathy and intralesional vascularity. USG was most accurate in diagnosing thyroiditis & adenoma followed by colloid nodules and least accurate in diagnosing malignant nodules. Conclusion: Gray scale ultrasound coupled with color doppler imaging can reliably differentiate benign from malignant lesions; or diagnose lesions of toxic goitre adenoma or thyroiditis. It also helps in determining the solid and cystic nature of nodule. The number of lesions are well demonstrated by USG. In difficulty cases, FNAC can be used to provide the tissue diagnosis.