Diagnostic value of acoustic radiation force impulse imaging for assessing superficial lymph nodes: A diagnostic accuracy study

The aim of this study was to assess the diagnostic value of acoustic radiation force impulse (ARFI) imaging for differentiating superficial lymph nodes. Virtual touch tissue imaging (VTI) grade and shear wave velocity (SWV) were analyzed and compared in 97 patients (65 women, 32 men; mean age, 49 y; range, 23–72 y) with 97 lymph nodes [23 chronic nonspecific reactive lymph nodes (CLNs), 38 metastatic lymph nodes (MLNs), and 36 blood and lymphatic system diseases lymph nodes (BLLNs)]. The elastography characteristics in patients with CLNs, MLNs, and BLLNs were compared using the nonparametric Kruskal-Wallis test and Mann-Whitney U test for continuous variables and categorical variables. The diagnostic performance of VTI grade and SWV were evaluated using the area under the receiver operating characteristic curve (AUC). The median of SWV of MLNs was significantly higher (2.90 m/s) than those of CLNs (2.15 m/s) and BLLNs (2.52 m/s). The VTI grade of MLNs was significantly higher than those of CLNs (P < .001) and BLLNs (P < .001). The sensitivity, specificity, accuracy, and AUC were 81.58%, 95.65%, 86.89%, and 0.904, respectively, at a cutoff level of grade IV for VTI grade in differentiating MLNs from CLNs, whereas those of SWV were 57.89%, 86.96%, 68.85%, and 0.752, respectively, at a cutoff level of 2.76 m/s. The diagnostic performance of VTI grade was significantly higher than that of SWV in differentiating MLNs from CLNs. The diagnostic performance of VTI grade and SWV were lower intermediate in differentiating MLNs from BLLNs and in differentiating BLLNs from CLNs, and there was no significant difference between VTI grade and SWV. ARFI imaging may be a feasible method for differentiating MLNs from CLNs.