Role of sonoelastography beyond sonography for differentiation between reactive and metastatic lymphadenopathy

Purpose: To evaluate the diagnostic accuracy of sonography including Doppler and sonoelastography in differentiation between reactive and metastatic cervical lymphadenopathy. Materials and Methods: A cross-sectional study was undertaken with 50 study participants after defined inclusion and exclusion criteria as per the study needs and imaging limitations. Sonographic and sonoelastographic examination was done by two examiners and diagnosis was reached in consensus. Sonographic features assessed were size, short/long axis ratio, presence or absence of echogenic hilum, intra-nodal necrosis including pattern of vascularity. With ultrasonoelastography, color-coded elastograms and strain ratio (SR) were evaluated. Then, the accuracy of individual sonographic and sonoelastographic parameters as well as combined sonographic and sonoelastographic evaluation were evaluated against histopathological examination diagnosis. Cutoff for all the combined evaluation was determined from the receiver operating characteristic curve. Results: Sensitivity of individual sonographic parameters ranged from 81% to 96.3%, whereas specificity was from 50% to 96.3%. Maximum accuracy of 94.3% was obtained with intra-nodal necrosis and echogenic hilum individually. Color-coded elastograms with pattern >3 suggesting metastatic showed sensitivity of 100% but specificity of 75%. Maximum accuracy was achieved by SR >1.99 with 96.3% sensitivity and 93.02% specificity. Combined ultrasonography evaluation had sensitivity of 70.4% and specificity of 87.5%, whereas combined sonographic plus elastographic evaluation increased sensitivity and specificity to 92.6% and 100%, respectively. Conclusion: Combined sonographic and sonoelastographic assessment is better than individual assessment; hence, elastographic findings complement sonographic assessment and further increases the diagnostic confidence.