Comparison of Performance Characteristics of American College of Radiology TI-RADS, Korean Society of Thyroid Radiology TIRADS, and American Thyroid Association Guidelines

OBJECTIVE. The American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) provides guidelines to practitioners who interpret sonographic examinations of thyroid nodules. The purpose of this study is to compare the ACR TI-RADS system with two other well-established guidelines. MATERIALS AND METHODS. The ACR TI-RADS, the Korean Society of Thyroid Radiology (KSThR) Thyroid Imaging Reporting and Data System (TIRADS), and the American Thyroid Association guidelines were compared using 3422 thyroid nodules for which pathologic findings were available. The composition, echogenicity, margins, echogenic foci, and size of the nodules were assessed to determine whether a recommendation would be made for fine-needle aspiration or follow-up sonography when each system was used. The biopsy yield of malignant findings, the yield of follow-up, and the percentage of malignant and benign nodules that would be biopsied were determined for all nodules and for nodules 1 cm or larger. RESULTS. The percentage of nodules that could not be classified was 0%, 3.9%, and 13.9% for the ACR TI-RADS, KSThR TIRADS, and ATA guidelines, respectively. The biopsy yield of malignancy was 14.2%, 10.2%, and 10.0% for nodules assessed by the ACR -TI-RADS, KSThR TIRADS, and ATA guidelines, respectively. The percentage of malignant nodules that were biopsied was 68.2%, 78.7%, and 75.9% for the ACR TI-RADS, the KSThR TIRADS, and the ATA guidelines, respectively, whereas the percentage of malignant nodules that would be either biopsied or followed was 89.2% for the ACR TI-RADS. The percentage of benign nodules that would be biopsied was 47.1%, 79.7%, and 78.1% for the ACR -TI-RADS, the KSThR TIRADS, and the ATA guidelines, respectively. The percentage of benign nodules that would be either biopsied or followed was 65.2% for the ACR TI-RADS. CONCLUSION. The ACR TI-RADS performs well when compared with other well-established guidelines.