Diagnostic value of contrast-enhanced ultrasound combined with serum procalcitonin in tuberculous lymph nodes and metastatic lymph nodes

Abstract

Objective: To investigate the value of Contrast-Enhanced Ultrasound (CEUS) combined with Procalcitonin (PCT) in differentiating Tuberculous Lymph Nodes (TLN) from Metastatic Lymph Nodes (MLN). Methods: This prospective cohort study included 207 consecutive patients diagnosed with CTL. Before confirming through pathology or laboratory tests, every patient received standard ultrasound, CEUS, and MRI examinations, with the imaging results analyzed afterward. Serum indicators were measured by Enzyme-Linked Immunosorbent Assay (ELISA). Predictive modeling was performed by multifactorial logistic regression. Evaluate the diagnostic and calibration performance of the predictive model by drawing Receiver Operating Characteristic (ROC) curves and calibration curves, and using Area Under the Curve (AUC) and Hosmer-Lemeshow (H-L) tests. Results: The presence of lymph node lesions was confirmed by routine ultrasound and MRI in 207 patients, of which 102 (49.27%) had a pathological or laboratory diagnosis of metastatic lymph nodes (MLN), and 50.8 % were tuberculous lymph nodes (TLN). According to imaging findings of CEUS, TLN was more commonly associated with enhanced concentric performance in the arterial phase (67.65% vs. 40.95%) and heterogeneous enhancement pattern in lymph nodes (70.59% vs. 52.38%). Peak Intensity (PI) of lesions was higher in patients with MLN. Increased age-enhanced concentric performance in the arterial phase, increased PI, and serum PCT greater than 5.39 ng/mL were independent risk factors for MLN. The prediction model of serum PCT combined with CEUS had a higher diagnostic value for MLN. The H-L test indicated a satisfactory model fit (all p > 0.05), and the calibration curve closely approximates the ideal diagonal. Conclusion: CEUS combined with serum PCT has better clinical application value in the differential diagnosis of TLN and MLN.