The Role of the ACR TI-RADS Scoring System to Evaluate Solid and Cystic Thyroid Nodules Compared With Those Solid Nodules With or Without Echogenic Foci and Their Cytology Results

Objective: The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) is a reporting system for thyroid nodules detected with sonography and proposed by the ACR. The scoring of punctate echogenic foci (PEF) increases the TI-RADS score and leads to a biopsy of many thyroid nodules, otherwise found clinically. The aim of this study was to assess the risk of malignancy for mixed and solid nodules, with and without PEF, and cytologic correlation. Materials and Methods: Thyroid sonograms and ultrasound-guided thyroid biopsies were performed, at a University of Iowa Hospitals & Clinics for 105 patients, during July 2019 to June 2020. All these retrospective clinical studies were reviewed against the cytologic examinations. Results: Based on the 189 thyroid nodule biopsies reviewed, 82.5% were benign compared with 17.5% malignant lesions. A solid nodule composition was noted in 35.2%, and had a higher risk for malignancy, compared with 7.7% of the mixed nodules. There was a 33.3% incidence of malignancy for solid nodules with PEF, compared with 35.8% of lesions lacking PEF. For mixed nodules, 6.2% nodules demonstrated PEF and 7.7% of nodules, without PEF, were malignant. Conclusion: In this cohort, solid nodules had a higher risk of malignancy than mixed nodules. PEF did not increase the risk of malignancy in either solid or mixed thyroid nodules, in these patients. These findings would suggest that existing guidelines may overestimate the value of PEF in scoring, as well as determining which thyroid nodules require biopsy.