Diagnostic accuracy of shear wave and strain elastography in differentiating benign and malignant thyroid nodules

Abstract

Objective: This study assesses diagnostic accuracy of shear wave elastography (SWE) and strain elastography (SE) for thyroid nodule characterization in keeping histopathology as gold standard. Methodology: It was analytical cross-sectional study at Dow Institute of Radiology (Dow University of Health Sciences) with 361 thyroid nodules from January 2022 to February 2023. Images were assessed using Thyroid Imaging Reporting and Data System (TIRADS) followed by ultrasound elastography (USE). SWE was evaluated by elasticity mean and standard deviation. SE was assessed by Parenchyma to Nodule Strain Ratio (PNSR) and Muscle to Nodule Strain ratio (MNSR). Predictive values of SWE, MNSR, and PNSR were concluded by receiver operating characteristic (ROC) curve. Results: Fine Needle Aspiration and Cytology (FNAC) confirmed malignant thyroid nodules in 66 cases (18.3%). Diagnostic indices, including sensitivity, specificity, and diagnostic accuracy, were calculated for SWE, MNSR and PNSR. The optimal cut-off value using the ROC co-ordinates was 36.0 kPa for SWE, 2.4 for MNSR and 2.75 for PNSR. The sensitivity, specificity and diagnostic accuracy of SWE were 87.8 %, 89.4 % and 89.1 % respectively. The sensitivity, specificity and diagnostic accuracy of MNSR were 87.8%, 91.5% and 90.8 % respectively. Whereas, sensitivity, specificity and diagnostic accuracy of PNSR were 80.3%, 95.5% and 92.7 % respectively. Conclusion: USE had moderate to high diagnostic performance, with overlapping results of SWE, MNSR, and PNSR. While SWE and MNSR had similar sensitivity, PNSR had highest Specificity and diagnostic accuracy giving it a respectable position in the study.