What is the key question?

• EBUS elastography has previously been suggested as a way to help differentiate benign and malignant lymph nodes although studies differ on the utility of elastography as a reliable measure. This study compares B-mode sonographic images (BSIs) and elastography images (EEIs) with pathology results in radiologically normal sized lymph nodes.

What is the bottom line?

• 149 LNs from 132 patients were examined by calculating the ratio of blue to overall area in the EEI (called the stiffness area ratio; SAR) and a receiver operating characteristic calculated.
• Median SARs in malignant nodes were significantly greater than SARs of benign nodes (0.58 vs 0.32, P<0.001). Utility of results was best at a SAR of 0.41 with sensitivity 88.2%, specificity 80.2%, PPV 78.9%, NPV 89% and diagnostic accuracy rate 83.9%. NPV was optimized by using a combination of BSIs and EEIs (96.6%).

Why read on?

• In radiologically normal sized lymph nodes, the use of elastography allows accurate distinction between normal and abnormal nodes. Using BSIs further increases the NPV of elastography.
• This study expands on the usefulness of elastography and may offer some more guidance on which nodes to biopsy as part of a comprehensive mediastinal EBUS assessment.