Validation of the New Thyroid Imaging Reporting and Data System (TIRADS) From 2017 Risk Assessment of Thyroid Nodules in Comparison to the American Thyroid Association (ATA) Guidelines From 2015

Thyroid nodules are a very common clinical problem with prevalence of up to 68% in adults on high-resolution ultrasound .Ultrasound used in order to differentiate between benign and malignant lesion in the thyroid has shown sensitivity of 93.8% and specificity of 66% and US guided ( Fine needle aspiration ) FNA is known to be the test of choice with sensitivity and specificity were 89.5% and 98%, respectively in order to determine the nodules nature, . Four to 6.5 % of all nodules are malignant .There are several guidelines that were suggested to help predict the risk stratification of thyroid nodules by ultrasound .

The American Thyroid Association (ATA) guidelines which characterized the nodule by its size, echogenicity, shape, presence or absence of calcification and evidence of Extrathyroidal extension (ETE) is widely use as evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy and management of thyroid nodules. These nodule characteristics classify the risk for malignancy into five categories which include benign pattern, very low suspicion pattern, low suspicion pattern, intermediate suspicious pattern and high suspicion pattern .

The recent ACR TIRADS is a reporting system for thyroid nodules on ultrasound proposed by the American College of Radiology (ACR) published april 2017 that uses a slightly different scoring system for recommendation for FNA of thyroid nodules .The ultrasound features set by TIRADS include composition, echogenicity, shape, margins and echogenic foci. The scoring range according suspicion of malignancy.

The aim of this study is to validate TIRADS ACR 2017 risk stratification in the patient population in comparison to ATA risk stratification.

Methods