A Comparative Evaluation of Strain and Shear Wave Ultrasound Elastography for Characterizing Cervical Lymphadenopathy

TL;DR

This study compares strain and shear wave ultrasound elastography to help distinguish between benign and malignant cervical lymph nodes, reducing the need for invasive tests.

Contribution

The study evaluates the diagnostic accuracy of strain and shear wave elastography for cervical lymphadenopathy using a large patient cohort.

Findings

Malignant lymph nodes showed significantly higher elasticity and strain ratio compared to benign nodes.

Shear wave elastography achieved 100% sensitivity and 85% specificity for malignancy detection.

Strain ratio cutoff of 1.465 provided 91.5% sensitivity and 99% specificity.

Abstract

Background: Cervical lymphadenopathy has varied causes, from benign infections to malignancy. Accurate differentiation is crucial for staging and treatment. While fine needle aspiration cytology and histopathology are considered the gold standards, they are invasive procedures. Conventional ultrasound offers structural and vascular assessment but limited specificity. Elastography, including strain elastography and shear wave elastography (SWE), measures tissue stiffness, which is typically higher in malignancies.

Aim: This study aimed to assess the role of strain and SWE in differentiating benign from malignant cervical lymph nodes.

Methods: In this cross-sectional study at a tertiary care center, 97 cervical lymph nodes from patients aged 5-60 years were evaluated with B-mode ultrasound, color Doppler, strain ratio, and SWE. Histopathology/cytology served as the reference. Receiver operating characteristic analysis determined diagnostic performance.

Results: Malignancy was associated with older age, female sex, levels II and IV, absent hilum, heterogeneous echotexture, and peripheral vascularity (t = -3.64, p = 0.001). Malignant nodes had higher mean elasticity (72.06 vs. 9.23 kPa) and strain ratio (2.30 vs. 1.18) (t = -3.64, p = 0.001). SWE velocity cutoff 2.195 m/s achieved 100% sensitivity and 85% specificity (area under the curve, AUC = 0.940). A strain ratio cutoff of 1.465 achieved 91.5% sensitivity and 99% specificity (AUC = 0.956).

Conclusion: Strain and SWE, combined with conventional US, provide high accuracy in differentiating cervical lymph node pathology, thereby reducing the need for unnecessary invasive procedures.

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