English

Abstract

INTRODUCTION: In community, population older than fifty years of age, about 50% develop thyroid nodules. Among them 5% of these nodules are malignant, But it does not eliminate the need to screen benign nodules and differentiate it from malignant nodules. Ultrasonography of neck in general population detects 15 to 90%, having Thyroid nodules. Thyroid scan-B mode shows characters like dimension, contour, echogenicity, presence and type of peripheral halo. It also demonstrates the number of nodules. But, usual B mode USG cannot differentiate benign nodules from malignant nodules. In evaluation of thyroid swelling, FNAC plays a vital role. But, FNAC is not always diagnostic (eg. suspicious findings, insufficient materials, false positive or non diagnostic results). This can occur up to about 28% of samples. Moreover FNAC cannot differentiate follicular adenoma from follicular carcinoma. These limitations can be bridged by using high frequency Doppler scan that can detect blood flow in thyroid gland and other superficial tissues. It is based on the simple principle that increase in vascularity is associated with increased proliferation of cells. Doppler USG provides information about nodule vascularisation and is useful in identification of at risk nodules for malignancy by analyzing various parameters like resistance index, pulsatility index and filling patterns. AIM OF THE STUDY: 1. To Evaluate that Doppler USG is useful in diagnosing thyroid nodules at risk for malignancy, more importantly in differentiating benign follicular neoplasm from malignant follicular neoplasm. 2. It aids in management of patients with solitary nodule of thyroid with high risk for malignancy that they may directly undergo total thyroidectomy rather than going for hemithyroidectomy and later for second stage completion thyroidectomy. MATERIALS AND METHODS: In my study One hundred seventy seven patients with solitary thyroid nodule were analysed, sex distribution found to be 171 women & 6 men at our hospital. Age distribution found to be 15 to 75 years (mean 42 years). Once the presence of thyroid nodules were confirmed clinically, FNAC was done. These people were subjected to ultrasound neck along with Doppler imaging, We included only the nodules for which representative cytological material was available in FNAC. Ethical committee clearance was obtained and patients were enrolled for study after getting informed consent. All Doppler scans were performed with Siemens accuson, high frequency variable linear transducer, frequency used is 10 MHz (7.5MHz to 10MHz). Microscopic study of the FNAC specimens demonstrated that 119 of the 177 nodules were benign, 29 had indeterminate cytology (follicular cells/neoplasm) and 29 were malignant. In 29 patients with follicular cytology, 27 were proceeded with surgery and post op biopsy revealed 19 patients with benign disease and 8 patients with malignant disease. In this group of patients preoperative Doppler studies were correlated with post operative biopsy. In other patients Doppler studies were compared with FNAC CONCLUSION: USG evaluation of thyroid nodules by using power doppler can effectively differentiate nodules with high risk for malignancy from benign nodules. Power Doppler and RI have a high sensitivity and specificity in detecting malignancy. Patients showing follicular cells in FNAC can reliably be differentiated in to benign and malignant groups using Doppler sonogram, which can bridge the limitation of FNAC which cannot identify malignant follicular neoplasm