A retrospective study of reducing unnecessary thyroid biopsy for American College of Radiology Thyroid Imaging Reporting and Data Systems 4 assessment through applying shear wave elastography

Abstract

Objective The purpose of the study is to quantitatively assess shear-wave elastography (SWE) value in American College of Radiology Thyroid Imaging Reporting and Data Systems (ACR TI-RADS) 4. Materials and methods One hundred and fifty-two ACR TI-RADS 4 thyroid nodules undergoing SWE were included in the study. The mean (EMean), minimum (EMin) and maximum (EMax) of SWE elasticity were measured. Results The areas under the receiver operating characteristic (ROC) curves for SWE EMean, EMin and EMax in detecting benign and malignant nodules were 0.95, 0.83 and 0.84, respectively. Cut-off value of EMean ≤ 23.30 kPa is able to downgrade the lesion category to ACR TI-RADS 3 and cut-off value of EMean ≥ 52.14 kPa is able to upgrade the lesion category to ACR TI-RADS 5. Conclusions The EMean of SWE will probably identify nodules that have a high potential for benignity in ACR TI-RADS 4. It may help identify and select benign nodules while reducing unnecessary biopsy of benign thyroid nodules.

Figure 1. Schematic diagram of ACR TI-RADS was showing in the figure.

Figure 2. Two hundred and fifty-six ACR TI-RADS 4 lesions were evaluated in the initial analysis. One hundred and four lesions were excluded for some reasons as shown in figure. The remaining 152 lesions were used for the final analysis.

Figure 3. The SWE value of mean (EMean), min (EMin) and max (EMax) with areas under the receiver operative characteristic (ROC) curve of 0.95, 0.83 and 0.84, respectively.

Figure 4. According to composition (solid), echogenicity (very hypoechoic), shape (wider than tall), margin (smooth) and echogenic foci (none), this nodule was ACR TI-RADS 4 with 5 points. The EMean of SWE was 18.85 kPa which was able to downgrade the lesion category to ACR TI-RADS 3. The pathology of this nodule was nodular hyperplasia.