Quantitative shear wave elastography in the evaluation of metastatic cervical lymph nodes

Our aim was to compare the diagnostic performance of shear wave elastography (SWE) with that of gray-scale ultrasound (US) in differentiating metastatic from benign lymph nodes in patients with head and neck malignancies. Maximum shear elasticity modulus (maxSM) was measured on SWE. The reference standard was pathologic diagnosis after surgery. We examined 67 lymph nodes (34 metastatic, 33 benign) from 15 patients (8 men and 7 women; mean age, 54.2 years). The maxSM value was significantly higher for metastatic than benign lymph nodes (41.06 ± 36.34 kPa vs. 14.22 ± 4.19 kPa, p < 0.0001) at a cutoff level of 19.44 kPa. Accuracy, sensitivity and specificity were 94, 91 and 97%, respectively, for SWE, and 91, 88 and 94%, respectively, for gray-scale US. Multiple regression analysis showed that the maxSM value (r = 0.882) and gray-scale US criteria (r = 0.837) were independent variables. SWE may be a valuable quantitative reproducible method for characterizing cervical lymph nodes.