The value of contrast-enhanced ultrasound versus shear wave elastography in differentiating benign and malignant superficial lymph node lesions

Abstract

Objective: To analyze the value of contrast-enhanced ultrasound (CEUS) versus shear wave elastography (SWE) in differentiating benign and malignant superficial lymph node lesions.

Methods: In this retrospective study, a total of 140 superficial lymph nodes from 140 patients pathologically confirmed to have an enlargement of their superficial lymph nodes were examined using CEUS and SWE. The results and diagnostic efficacy were analyzed.

Results: Among the 67 benign lymph nodes, there were 38 cases of type I, 17 of type II, and 12 of types III and IV. Among the 73 malignant lymph nodes, there were 53 cases of type III, 11 of type IV, and 9 of types I and II. Among the patients with lymph nodes <1 cm, there were 20, 4, 8, and 5 cases of types I, II, III, and IV, respectively. Among the patients with 1-2 cm lymph nodes, there were 15, 10, 26 and 7 cases of types I, II, III, and IV, respectively. There were 6, 10, 27, and 2 cases of types I, II, III, and IV in the >2 cm lymph nodes, respectively. The accuracy, sensitivity, and specificity of CEUS in the diagnosis of malignant lymph nodes were 85.00%, 87.67%, and 82.09%, respectively, and those of SWE were 89.29%, 80.82%, and 98.51%, respectively. SWE showed higher specificity than CEUS (P<0.05). SWE showed mean shear wave velocity (SWV) values of (2.11±0.41) m/s for the benign lymph nodes and (3.22±0.79) m/s for the malignant lymph nodes (P<0.05). The receiver operating characteristic (ROC) curves of the SWV values for the benign and malignant lymph nodes showed AUC=0.9948.

Conclusion: Both CEUS and SWE are valuable in the differentiation of benign and malignant lymph node lesions, but SWE has a higher specificity. The SWV value of SWE is superior in the differentiation of benign and malignant lymph nodes. The combination of the two methods can achieve a higher accuracy.

Keywords: Superficial lymph nodes; benign; differentiation; malignant; shear wave elastography; ultrasonography.

Figure 1

Gray-scale ultrasound images of lymph nodes. A: A 2D sonogram of a normal lymph node, with a normal morphology and distinct cortical and medullary structures; B, C: 2D ultrasound sonograms of metastatic lymph nodes with abnormal morphology (distorted aspect ratio), poorly defined cortical and medullary structures, and a peripheral pattern.

Figure 2

SWV values. A: A scatter plot of the SWV values of the benign and malignant lymph nodes; B: A comparison of the mean SWV values of the benign and malignant lymph nodes, *P<0.05.

Figure 3

ROC curves of the SWV values used for differentiating the benign and malignant lymph nodes. AUC=0.9948, 95% CI of 0.9882-1.0000, SE=0.003379, P<0.0001.