Sonographic evaluation of cervical lymphadenopathy: is power Doppler sonography routinely indicated?

Routine sonographic examination of neck nodes now includes both grey-scale and Doppler sonography. Although the addition of Doppler sonography to the well-established practice of grey-scale sonography increases the amount of information obtained by sonography, it also increases the examination time, particularly if spectral Doppler and estimation of vascular resistance is performed. This study was, therefore, undertaken to evaluate whether Doppler sonography is routinely indicated in every case or its use should be limited to those cases where grey-scale sonography is equivocal. We evaluated the grey-scale and power Doppler sonograms of 101 fine-needle aspiration cytology (FNAC)-proven metastatic nodes and 72 FNAC-proven nonmetastatic nodes. All lymph nodes were evaluated with grey-scale and power Doppler sonography. The shape, echogenicity, internal architecture, vascular distribution and vascular resistance of the lymph nodes were evaluated. Grey-scale sonographic features evaluated in this study had a high sensitivity (95%) and specificity (83%) in classifying metastatic and nonmetastatic nodes. Metastatic and nonmetastatic lymph nodes that could not be classified by grey-scale sonography demonstrated Doppler features that helped in their correct identification. Power Doppler sonography is not necessary for every case in routine clinical practice, but is essential and useful in patients where grey-scale sonography is equivocal. In this study, power Doppler sonography aided in the diagnosis in 5% and 17% of patients with metastatic and nonmetastatic nodes, respectively.