Diagnostic performance of ultrasound elastography combined with ACR TI-RADS for thyroid nodule assessment: a systematic review and meta-analysis

<div style="text-align: left;"><strong><span lang="EN-US">Introduction: </span></strong><span lang="EN-US">Thyroid nodules are common, and most are benign. Risk stratification is important for detection of malignancy and avoidance of unnecessary fine-needle aspiration (FNA). The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) provides standardized ultrasound-based assessment, and elastography has been suggested as an adjunct. This study aimed to evaluate the diagnostic performance of elastography combined with ACR TI-RADS and its impact on biopsy recommendation. </span></div> <div style="text-align: left;">&nbsp;</div> <div style="text-align: left;"><span lang="EN-US"><strong>Methods:</strong> This systematic review and meta-analysis followed PRISMA guidelines and registered a priori in PROSPERO. Studies assessing the combined method of elastography plus ACR TI-RADS in correlation with histopathology and/or fine-needle aspiration cytology were included. Pooled sensitivity and specificity were calculated through a bivariate random-effect model, and diagnostic performance was assessed by hierarchical summary receiver operating characteristic analysis. </span></div> <div style="text-align: left;">&nbsp;</div> <div style="text-align: left;"><span lang="EN-US"><strong>Results:</strong> Fifteen studies were selected. The pooled sensitivity, specificity, and area under the curve (AUC) of ACR TI-RADS alone were 84.1%, 76.0%, and 0.874, respectively. Adding elastography raised sensitivity to 90.5% but reduced specificity to 18.8%, with a lower AUC of 0.711. The pooled estimate indicated 41.1% of biopsies could be potentially avoided, but the estimate was compromised by substantial heterogeneity (I²=98.4%) and limited generalizability. The combined false-negative rate was 3.0% with significant heterogeneity. </span></div> <div style="text-align: left;">&nbsp;</div> <div style="text-align: left;"><span lang="EN-US"><strong>Conclusions:</strong> In our study, ACR TI-RADS alone showed more balanced </span>performance than the combined systems. Adding elastography increased sensitivity but decreased specificity and overall diagnostic accuracy. Evidence on biopsy reduction is uncertain due to high heterogeneity. These results do not support routine elastography for reducing FNA, but selective adjunctive use warrants further prospective studies.</div>